Astronomy

What are the Similarities and Differences between ALMA and FAST?

What are the Similarities and Differences between ALMA and FAST?


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What are the Similarities and Differences between ALMA (Atacama Large Millimeter Array) and FAST (Five hundred meter aperture spherical telescope)?

What can they see, what's their resolution like? How do they compare?


This is quite a broad question, since there are far more differences than similarities between the two. This answer will focus on the first part of the question and be about the technical aspects of the two telescopes.

  1. Basics: FAST is a "classic" filled aperture telescope. This means it consists of a single large dish that focuses incoming radio waves on a single receiver (this is simplified). In contrast, ALMA is an interferometer: Many (> 60) dishes each focus incoming radiation on their own receiver. The relative positions of the individual telescopes is known to great precsion, and both amplitude and phase of the incoming radiation measured, which allows astronomers to combine several or all of the telescopes for a single observation. The maximum achievable resolution is then not determined by the diameter of a telescope but by the distance between those furthest apart. (Again, this is greatly simplified; interferometry is complicated.) In principle, FAST could also become part of a huge interferometer called VLBA.
  2. Wavelength: FAST is a "classic" radio telescope, observing in the centimeter to meter wavelength range. ALMA is a sub-mm telescope operating at smaller wavelengths of 0.3 mm to about 1 cm.
  3. Resolution: since the resolution is $ propto lambda / d$, with $lambda$ the wavelength and $d$ the diameter of the telescope, ALMA has a much higher resolution - smaller $lambda$ and greater $d$. ALMAs resolution is given as 10 milliarcseconds, while in the ideal case FASTs is $1.22 cdot 0.1 / 500 cdot( 180 / pi cdot 3600) = 50$ arcseconds at 10 cm wavelength. For comparison, according to wikipedia the unaided human eye has a resolution of about 60 arcseconds.
  4. Sensitivity:
    1. Atmospheric transmission: FAST observes in a wavelength regime in which our atmosphere is quite transparent. In contrast, the ALMA dishes are located in one of the driest deserts of the world at an altitude of over 5000 m, in order to minimize the effects of water vapour in the atmosphere.
    2. Collecting area: FAST has a much larger collecting area. Also (I'm uncertain in this point, please correct this if I'm wrong) you lose some sensitivity when doing interferometry compared to just pooling the collecting areas of the single telescopes in ALMA.
  5. Point Spread Function: The PSF of a single telescope, even a radio telescope, is much simpler than that of an interferometer. So the data analysis required to turn observations into an image should be much more straightforward for FAST.

There are some differences in the required surface accuracy (imperfections significantly smaller in scale than the observed wavelength do not matter) and surface composition - the ALMA dishes are solid metal, whereas the FAST dish is perforated. This works because as long as the holes are smaller than the wavelength, the incoming radio waves see it as solid.

The receivers used to convert incoming photons to electricity for both telescopes work on the same principles. Practically, it is much more difficult for ALMA due to the high frequencies at the edge of the far-infrared spectrum. ALMAs shortest wavelengths are just a little too long for receivers used in infrared or optical telescopes to work, and almost too short for normal radio receivers to work.


Cosmic cartographers map nearby Universe revealing the diversity of star-forming galaxies

IMAGE: Using the Atacama Large Millimeter/submillimeter Array (ALMA) scientists conducted a census of nearly 100 galaxies in the nearby Universe. This census helped them to characterize the diverse appearances and behaviors. view more

Credit: ALMA (ESO/NAOJ/NRAO)/S. Dagnello (NRAO)

A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has completed the first census of molecular clouds in the nearby Universe, revealing that contrary to previous scientific opinion, these stellar nurseries do not all look and act the same. In fact, they're as diverse as the people, homes, neighborhoods, and regions that make up our own world.

Stars are formed out of clouds of dust and gas called molecular clouds, or stellar nurseries. Each stellar nursery in the Universe can form thousands or even tens of thousands of new stars during its lifetime. Between 2013 and 2019, astronomers on the PHANGS-- Physics at High Angular Resolution in Nearby GalaxieS-- project conducted the first systematic survey of 100,000 stellar nurseries across 90 galaxies in the nearby Universe to get a better understanding of how they connect back to their parent galaxies.

"We used to think that all stellar nurseries across every galaxy must look more or less the same, but this survey has revealed that this is not the case, and stellar nurseries change from place to place," said Adam Leroy, Associate Professor of Astronomy at Ohio State University (OSU), and lead author of the paper presenting the PHANGS ALMA survey. "This is the first time that we have ever taken millimeter-wave images of many nearby galaxies that have the same sharpness and quality as optical pictures. And while optical pictures show us light from stars, these ground-breaking new images show us the molecular clouds that form those stars."

The scientists compared these changes to the way that people, houses, neighborhoods, and cities exhibit like-characteristics but change from region to region and country to country.

"To understand how stars form, we need to link the birth of a single star back to its place in the Universe. It's like linking a person to their home, neighborhood, city, and region. If a galaxy represents a city, then the neighborhood is the spiral arm, the house the star-forming unit, and nearby galaxies are neighboring cities in the region," said Eva Schinnerer, an astronomer at the Max Planck Institute for Astronomy (MPIA) and principal investigator for the PHANGS collaboration "These observations have taught us that the "neighborhood" has small but pronounced effects on where and how many stars are born."

To better understand star formation in different types of galaxies, the team observed similarities and differences in the molecular gas properties and star formation processes of galaxy disks, stellar bars, spiral arms, and galaxy centers. They confirmed that the location, or neighborhood, plays a critical role in star formation.

"By mapping different types of galaxies and the diverse range of environments that exist within galaxies, we are tracing the whole range of conditions under which star-forming clouds of gas live in the present-day Universe. This allows us to measure the impact that many different variables have on the way star formation happens," said Guillermo Blanc, an astronomer at the Carnegie Institution for Science, and a co-author on the paper.

"How stars form, and how their galaxy affects that process, are fundamental aspects of astrophysics," said Joseph Pesce, National Science Foundation's program officer for NRAO/ALMA. "The PHANGS project utilizes the exquisite observational power of the ALMA observatory and has provided remarkable insight into the story of star formation in a new and different way."

Annie Hughes, an astronomer at L'Institut de Recherche en Astrophysique et Planétologie (IRAP), added that this is the first time scientists have a snapshot of what star-forming clouds are really like across such a broad range of different galaxies. "We found that the properties of star-forming clouds depend on where they are located: clouds in the dense central regions of galaxies tend to be more massive, denser, and more turbulent than clouds that reside in the quiet outskirts of a galaxy. The lifecycle of clouds also depends on their environment. How fast a cloud forms stars and the process that ultimately destroys the cloud both seem to depend on where the cloud lives."

This is not the first time that stellar nurseries have been observed in other galaxies using ALMA, but nearly all previous studies focused on individual galaxies or part of one. Over a five-year period, PHANGS assembled a full view of the nearby population of galaxies. "The PHANGS project is a new form of cosmic cartography that allows us to see the diversity of galaxies in a new light, literally. We are finally seeing the diversity of star-forming gas across many galaxies and are able to understand how they are changing over time. It was impossible to make these detailed maps before ALMA," said Erik Rosolowsky, Associate Professor of Physics at the University of Alberta, and a co-author on the research. "This new atlas contains 90 of the best maps ever made that reveal where the next generation of stars is going to form."

For the team, the new atlas doesn't mean the end of the road. While the survey has answered questions about what and where, it has raised others. "This is the first time we have gotten a clear view of the population of stellar nurseries across the whole nearby Universe. In that sense, it's a big step towards understanding where we come from," said Leroy. "While we now know that stellar nurseries vary from place to place, we still do not know why or how these variations affect the stars and planets formed. These are questions that we hope to answer in the near future."

Ten papers detailing the outcomes of the PHANGS survey are presented this week at the 238th meeting of the American Astronomical Society.

PHANGS-ALMA: Arcsecond CO(2-1) Imaging of Nearby Star-Forming Galaxies, Leroy et al. ApJS accepted, preview [https:/ / arxiv. org/ abs/ 2104. 07739]

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Media Contact:

Amy C. Oliver
Public Information Officer, ALMA
Public Information & News Manager, NRAO
+1 434 242 9584
[email protected]

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.


Contents

The telescope was first proposed in 1994. The project was approved by the National Development and Reform Commission (NDRC) in July 2007. [15] A 65-person village was relocated from the valley to make room for the telescope [16] and an additional 9,110 people living within a 5 km radius of the telescope were relocated to create a radio-quiet area. [16] The Chinese government spent around $269 million in poverty relief funds and bank loans for the relocation of the local residents, while the construction of the telescope itself cost US$180 million . [17]

On 26 December 2008, a foundation laying ceremony was held on the construction site. [18] Construction started in March 2011, [19] [20] and the last panel was installed on the morning of 3 July 2016. [16] [20] [21] [22]

Originally budgeted for CN¥700 million, [3] : 49 [19] the final cost was CN¥1.2 billion ( US$180 million ). [16] [23] Significant difficulties encountered were the site's remote location and poor road access, and the need to add shielding to suppress radio-frequency interference (RFI) from the primary mirror actuators. [5] There are still ongoing problems with the failure rate of the primary mirror actuators. [5]

Testing and commissioning began with first light on 25 September 2016. [24] The first observations are being done without the active primary reflector, configuring it in a fixed shape and using the Earth's rotation to scan the sky. [5] Subsequent early science took place mainly in lower frequencies [25] while the active surface is brought to its design accuracy [26] longer wavelengths are less sensitive to errors in reflector shape. It took three years to calibrate the various instruments so it can become fully operational. [24]

Local government efforts to develop a tourist industry around the telescope are causing some concern among astronomers worried about nearby mobile telephones acting as sources of RFI. [27] A projected 10 million tourists in 2017 will force officials to decide on the scientific mission versus the economic benefits of tourism. [28]

The primary driving force behind the project [5] was Nan Rendong, a researcher with the Chinese National Astronomical Observatory, part of the Chinese Academy of Sciences. He held the positions of chief scientist [22] and chief engineer [5] of the project. He died on 15 September 2017 in Boston due to lung cancer. [29]

FAST has a reflecting surface 500 meters in diameter located in a natural sinkhole in the karst rock landscape), focusing radio waves on a receiving antenna in a "feed cabin" suspended 140 m (460 ft) above it. The reflector is made of perforated aluminium panels supported by a mesh of steel cables hanging from the rim.

FAST's surface is made of 4450 [16] triangular panels, 11 m (36 ft) on a side, [30] in the form of a geodesic dome. 2225 winches located underneath [5] make it an active surface, pulling on joints between panels, deforming the flexible steel cable support into a parabolic antenna aligned with the desired sky direction. [31]

Above the reflector is a lightweight feed cabin moved by a cable robot using winch servomechanisms on six support towers. [20] : 13 The receiving antennas are mounted below this on a Stewart platform which provides fine position control and compensates for disturbances like wind motion. [20] : 13 This produces a planned pointing precision of 8 arcseconds. [6]

The maximum zenith angle is 40 degrees when the effective illuminated aperture is reduced to 200 m, while it is 26.4 degrees when the effective illuminated aperture is 300 m without loss. [32] [3] : 13

Although the reflector diameter is 500 metres (1,600 ft), only a circle of 300 m diameter is used (held in the correct parabolic shape and "illuminated" by the receiver) at any one time. [20] : 13 The telescope can be pointed to different positions on the sky by illuminating a 300 meter section of the 500 meter aperture.

Its working frequency range of 70 MHz to 3.0 GHz, [33] with the upper limit set by the precision with which the primary can approximate a parabola. It could be improved slightly, but the size of the triangular segments limits the shortest wavelength which can be received. The original plan is to cover the frequency range with 9 receivers. During the construction phase, a commissioning ultra-wide band receiver covering 260 MHz to 1620 MHz was proposed and built . which produced the first pulsar discovery from FAST. [34] At the moment, only the FAST L-band Receiver-array of 19 beams (FLAN [7] ) is installed and is operational between 1.05 GHz and 1.45 GHz.

The Next Generation Archive System (NGAS), developed by the International Centre for Radio Astronomy Research (ICRAR) in Perth, Australia and the European Southern Observatory will store and maintain the large amount of data that it collects. [35]

A 5-kilometre zone near the telescope forbids tourists from using mobile phones and other radio-emitting devices [36]

The FAST website lists the following science objectives of the radio telescope: [37]

  1. Large scale neutral hydrogen survey observations
  2. Leading the international very long baseline interferometry (VLBI) network
  3. Detection of interstellar molecules
  4. Detecting interstellar communication signals (Search for extraterrestrial intelligence) [38]

The FAST telescope joined the Breakthrough Listen SETI project in October 2016 to search for intelligent extraterrestrial communications in the Universe. [39]

China's Global Times reported that its 500-meter (1,600 foot) FAST telescope will be open to the global scientific community starting in April of 2021 (when applications will be reviewed), and becoming effective in August 2021. Foreign scientists will be able to submit applications to China’s National Astronomical Observatories online. [40] [41]

The basic design of FAST is similar to the former Arecibo Telescope. Both designs had reflectors installed in natural hollows within karst limestone, made of perforated aluminium panels with a movable receiver suspended above and both have an effective aperture smaller than the physical size of the primary. There are however significant differences in addition to the size. [31] [42] [43]

First, Arecibo's dish was fixed in a spherical shape. Although it was also suspended from steel cables with supports underneath for fine-tuning the shape, they were manually operated and adjusted only during maintenance. [31] It had a fixed spherical shape with two additional suspended reflectors in a Gregorian configuration to correct for spherical aberration. [44]

Second, Arecibo's receiver platform was fixed in place. To support the greater weight of the additional reflectors, the primary support cables were static, with the only motorised portion being three hold-down winches which compensated for thermal expansion. [31] : 3 The antennas could move along a rotating arm below the platform, to allow limited adjustment of azimuth. [31] : 4 This smaller range of motion limited it to viewing objects within 19.7° of the zenith. [45]

Third, Arecibo could receive higher frequencies. The finite size of the triangular panels making up FAST's primary reflector limits the accuracy with which it can approximate a parabola, and thus the shortest wavelength it can focus. Arecibo's more rigid design allowed it to maintain sharp focus down to 3 cm wavelength (10 GHz) FAST is limited to 10 cm (3 GHz). Improvements in position control of the secondary might be able to push that to 6 cm (5 GHz), but then the primary reflector becomes a hard limit.

Fourth, the FAST dish is significantly deeper, contributing to a wider field of view. Although 64% larger in diameter, FAST's radius of curvature is 300 m (980 ft), [20] : 3 barely larger than Arecibo's 270 m (870 ft), [45] so it forms a 113° arc [20] : 4 (vs. 70° for Arecibo). Although Arecibo's full aperture of 305 m (1,000 ft) could be used when observing objects at the zenith, this was only possible with the line feed which had a very narrow frequency range and had been unavailable due to damage since 2017. [46] Most Arecibo observations used the Gregorian feeds, where the effective aperture was approximately 221 m (725 ft) at zenith [46] . [31] : 4

Fifth, Arecibo's larger secondary platform also housed several transmitters, making it one of only two instruments in the world capable of radar astronomy. [ citation needed ] The NASA-funded Planetary Radar System allowed Arecibo to study solid objects from Mercury to Saturn, and to perform very accurate orbit determination on near-earth objects, particularly potentially hazardous objects. Arecibo also included several NSF funded radars for ionospheric studies. Such powerful transmitters are too large and heavy for FAST's small receiver cabin, so it will not be able to participate in planetary defense although in principle it could serve as a receiver in a bistatic radar system.

It appeared in the episode "The Search for Intelligent Life on Earth" of the television series Cosmos: Possible Worlds presented by Neil deGrasse Tyson.


Research Highlights Key Differences between Human and Non-Human Primate Brains

A detailed comparative analysis of adult human, chimpanzee, and macaque brains shows that all regions of the human brain have molecular signatures very similar to those of our primate relatives, yet some regions contain distinctly human patterns of gene activity that mark the brain’s evolution and may contribute to our cognitive abilities.

Sousa et al show that the human brain is not only a larger version of the ancestral primate brain but also one filled with distinct and surprising differences. Image credit: William H. Calvin / CC BY-SA 4.0.

“Our brains are three times larger, have many more cells and therefore more processing power than chimpanzee or monkey. Yet there are also distinct small differences between the species in how individual cells function and form connections,” said co-lead author Dr. Andre Sousa, a postdoctoral researcher at the Yale School of Medicine.

To pinpoint differences among primate brains, Dr. Sousa and co-authors evaluated brain tissue samples from six humans, five chimpanzees, and five macaques.

They generated transcriptional profiles of 247 tissue samples in total, representing several different brain regions (hippocampus, amygdala, striatum, mediodorsal nucleus of thalamus, cerebellar cortex, and neocortex).

“We found striking similarities between primate species of gene expression in 16 regions of the brain — even in the prefrontal cortex, the seat of higher order learning that most distinguishes humans from other apes,” they researchers said.

“However, our study showed the one area of the brain with the most human-specific gene expression is the striatum, a region most commonly associated with movement.”

“Distinct differences were also found within regions of the brain, even in the cerebellum, one of the evolutionarily most ancient regions of the brain, and therefore most likely to share similarities across species.”

The team found one gene, ZP2 (zona pellucida glycoprotein 2), was active in only human cerebellum — a surprise, because the same gene had been linked to sperm selection by human ova.

“We have no idea what it is doing there,” said co-lead author Dr. Ying Zhu, also from the Yale School of Medicine.

The authors also focused on one gene, TH (tyrosine hydroxylase), which is involved in the production of dopamine, a neurotransmitter that regulates motor behavior, motivation, pleasure and emotional arousal.

They found that the TH gene was highly expressed in human neocortex and striatum but absent from the neocortex of chimpanzees.

“The neocortical expression of this gene was most likely lost in a common ancestor and reappeared in the human lineage,” Dr. Sousa said.

The team also found higher levels of expression of the gene MET, which is linked to autism spectrum disorder, in the human prefrontal cortex compared to the other primates tested.


Similarities and Differences in the Medium

A Navier–Stokes fluid (such as air) is an isotropic medium that obeys the Navier–Stokes equation for momentum transport

where ρ is the mass density of the fluid, P is an isotropic pressure, and ν is the kinematic viscosity. In this medium, momentum is transferred locally from one element of fluid to the adjacent elements via the stress tensor and via ∇P. In transporting momentum long distances, one element transfers its momentum to a neighbor, which in turn transports its momentum to its neighbor, and so forth. In the Navier–Stokes equation, momentum transport occurs at a sound speed ~P/ρ.

A collisionless magnetized plasma (such as the solar wind) is anisotropic on global and local scales. It is anisotropic globally in that the magnetic structure of the plasma can propagate without evolution in the direction of the global mean magnetic-field vector (cf. Figure 7.1 of Parker, 1979 Borovsky J. E., 2020a Nemecek et al., 2020), and it is anisotropic locally in that the nature of the forces perpendicular and parallel to the local magnetic-field vector B differs. In the MHD description of plasmas, the momentum transport is given by

where j is the electrical current density in the plasma. In the direction parallel to B, the j × B term of expression (2) vanishes, and the MHD description reduces to the Navier–Stokes equation (expression 1). A collisionless plasma has fluid-like properties in the directions perpendicular to B where the magnetic field constrains the charged particles of the plasma to orbit the magnetic-field lines together (e.g., Chew et al., 1956 Parker, 1957), but in the direction along B, the particles of the plasma travel ballistically. In a collisionless plasma parallel to B, momentum is transported at the speed of the individual particles (e.g., ions), and momentum is not shared with neighboring parcels of plasma. Occasional warnings have appeared about the use of MHD to describe the collisionless solar wind (e.g., Lemaire and Scherer, 1973 Montgomery, 1992). As pointed out by Borovsky and Gary (2009), the solar-wind plasma fails fluid-behavior tests in the parallel-to-B direction. Three examples are the following. (1) The ballistic-ion behavior along B observed when the solar-wind plasma and the magnetospheric plasma are magnetically joined by field-line reconnection (Paschmann, 1984 Thomsen et al., 1987) fluid behavior would produce a local sharing of momentum and a separation of the two reconnected plasmas, rather than the long-distance interpenetration of the ion populations that is seen. (2) The inability of the solar-wind plasma to form a stationary bow shock when the shock-normal angle is parallel to the solar-wind magnetic field (Thomsen et al., 1990 Mann et al., 1994 Wilkinson, 2003 Lucek et al., 2004). (3) The strictly particle-kinetic dynamics along B of the solar-wind as it fills in the wake created by flow past the moon (Ogilvie et al., 1996 Farrell et al., 2002).

This difference is noted as item 1 in Table 2.

Table 2. A summary of differences between the Navier–Stokes turbulence in the wind tunnel and the Alfvénic fluctuations of the fast solar wind.


Cosmic cartographers map nearby Universe revealing the diversity of star-forming galaxies

A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has completed the first census of molecular clouds in the nearby Universe, revealing that contrary to previous scientific opinion, these stellar nurseries do not all look and act the same. In fact, they’re as diverse as the people, homes, neighborhoods, and regions that make up our own world.

Stars are formed out of clouds of dust and gas called molecular clouds, or stellar nurseries. Each stellar nursery in the Universe can form thousands or even tens of thousands of new stars during its lifetime. Between 2013 and 2019, astronomers on the PHANGS– Physics at High Angular Resolution in Nearby GalaxieS– project conducted the first systematic survey of 100,000 stellar nurseries across 90 galaxies in the nearby Universe to get a better understanding of how they connect back to their parent galaxies.

“We used to think that all stellar nurseries across every galaxy must look more or less the same, but this survey has revealed that this is not the case, and stellar nurseries change from place to place,” said Adam Leroy, Associate Professor of Astronomy at Ohio State University (OSU), and lead author of the paper presenting the PHANGS ALMA survey. “This is the first time that we have ever taken millimeter-wave images of many nearby galaxies that have the same sharpness and quality as optical pictures. And while optical pictures show us light from stars, these ground-breaking new images show us the molecular clouds that form those stars.”

The scientists compared these changes to the way that people, houses, neighborhoods, and cities exhibit like-characteristics but change from region to region and country to country.

“To understand how stars form, we need to link the birth of a single star back to its place in the Universe. It’s like linking a person to their home, neighborhood, city, and region. If a galaxy represents a city, then the neighborhood is the spiral arm, the house the star-forming unit, and nearby galaxies are neighboring cities in the region,” said Eva Schinnerer, an astronomer at the Max Planck Institute for Astronomy (MPIA) and principal investigator for the PHANGS collaboration “These observations have taught us that the “neighborhood” has small but pronounced effects on where and how many stars are born.”

To better understand star formation in different types of galaxies, the team observed similarities and differences in the molecular gas properties and star formation processes of galaxy disks, stellar bars, spiral arms, and galaxy centers. They confirmed that the location, or neighborhood, plays a critical role in star formation.

“By mapping different types of galaxies and the diverse range of environments that exist within galaxies, we are tracing the whole range of conditions under which star-forming clouds of gas live in the present-day Universe. This allows us to measure the impact that many different variables have on the way star formation happens,” said Guillermo Blanc, an astronomer at the Carnegie Institution for Science, and a co-author on the paper.

“How stars form, and how their galaxy affects that process, are fundamental aspects of astrophysics,” said Joseph Pesce, National Science Foundation’s program officer for NRAO/ALMA. “The PHANGS project utilizes the exquisite observational power of the ALMA observatory and has provided remarkable insight into the story of star formation in a new and different way.”

Annie Hughes, an astronomer at L’Institut de Recherche en Astrophysique et Planétologie (IRAP), added that this is the first time scientists have a snapshot of what star-forming clouds are really like across such a broad range of different galaxies. “We found that the properties of star-forming clouds depend on where they are located: clouds in the dense central regions of galaxies tend to be more massive, denser, and more turbulent than clouds that reside in the quiet outskirts of a galaxy. The lifecycle of clouds also depends on their environment. How fast a cloud forms stars and the process that ultimately destroys the cloud both seem to depend on where the cloud lives.”

This is not the first time that stellar nurseries have been observed in other galaxies using ALMA, but nearly all previous studies focused on individual galaxies or part of one. Over a five-year period, PHANGS assembled a full view of the nearby population of galaxies. “The PHANGS project is a new form of cosmic cartography that allows us to see the diversity of galaxies in a new light, literally. We are finally seeing the diversity of star-forming gas across many galaxies and are able to understand how they are changing over time. It was impossible to make these detailed maps before ALMA,” said Erik Rosolowsky, Associate Professor of Physics at the University of Alberta, and a co-author on the research. “This new atlas contains 90 of the best maps ever made that reveal where the next generation of stars is going to form.”

For the team, the new atlas doesn’t mean the end of the road. While the survey has answered questions about what and where, it has raised others. “This is the first time we have gotten a clear view of the population of stellar nurseries across the whole nearby Universe. In that sense, it’s a big step towards understanding where we come from,” said Leroy. “While we now know that stellar nurseries vary from place to place, we still do not know why or how these variations affect the stars and planets formed. These are questions that we hope to answer in the near future.”

Ten papers detailing the outcomes of the PHANGS survey are presented this week at the 238th meeting of the American Astronomical Society.

PHANGS-ALMA: Arcsecond CO(2-1) Imaging of Nearby Star-Forming Galaxies, Leroy et al. ApJS accepted, preview [https:/ / arxiv. org/ abs/ 2104. 07739 ]

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Media Contact:

Public Information Officer, ALMA

Public Information & News Manager, NRAO

Media Contact
Amy C. Oliver
[email protected]


Growing up fast in the very early universe

An artist’s impression of a very dusty galaxy in the early universe that already exhibits signs of a rotating disc. Reds represent gast while blues and browns represent dust as seen by the ALMA radio telescope array. Image: B. Saxton NRAO/AUI/NSF, ESO, NASA/STScI NAOJ/Subaru

One might expect galaxies forming in the very early universe to be relatively free of dust and the heavy elements cooked up when successive generations of massive stars run out of nuclear fuel and explode in supernova blasts. That process takes time, and most infant galaxies could be expected to experience rapid growth spurts in the eventual transition between the “primordial” and “mature” stages in their development.

But in a survey of 118 young galaxies dating back to within 1 billion to 1.5 billion years after the Big Bang, astronomers were surprised to find many more mature galaxies than expected.

“We didn’t expect to see so much dust and heavy elements in these distant galaxies,” said Andreas Faisst of the Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology.

In fact, about 20 percent of the galaxies sampled in the survey “are already very dusty and a significant fraction of the ultraviolet light from newborn stars is already hidden by this dust,” said Daniel Schaerer of the University of Geneva.

Two galaxies in the early universe as imaged by ALMA in radio waves. Both are considered more “mature” than “primordial” based on the amounts of dust present (seen in yellow). Gas, seen in red, is used to measure obscured star formation and motion. Image: B. Saxton NRAO/AUI/NSF, ALMA (ESO/NAOJ/NRAO), ALPINE team

The ALMA Large Program to Investigate C+ at Early Times, or ALPINE, survey is the largest multi-wavelength study of galaxies in the early universe, utilising optical observations by ground- and space-based telescopes, including Keck, Subaru, the Very Large Telescope and the Hubble and Spitzer space telescopes and radio observations using the Atacama Large Millimetre/submillimetre Array, or ALMA.

The ALMA observations allowed researchers to detect star formation hidden by thick dust that blocks optical and infrared wavelengths and to follow the motion of gas associated with star-forming regions, finding “Hubble-dark galaxies” that even the space telescope cannot see.

“We want to see exactly where the dust is and how the gas moves around,” said Paolo Cassata of the University of Padua in Italy. “We also want to compare the dusty galaxies to others at the same distance and figure out if there might be something special about their environments.”


Description

Big Data in Radio Astronomy: Scientific Data Processing for Advanced Radio Telescopes provides the latest research developments in big data methods and techniques for radio astronomy. Providing examples from such projects as the Square Kilometer Array (SKA), the world’s largest radio telescope that generates over an Exabyte of data every day, the book offers solutions for coping with the challenges and opportunities presented by the exponential growth of astronomical data. Presenting state-of-the-art results and research, this book is a timely reference for both practitioners and researchers working in radio astronomy, as well as students looking for a basic understanding of big data in astronomy.

Big Data in Radio Astronomy: Scientific Data Processing for Advanced Radio Telescopes provides the latest research developments in big data methods and techniques for radio astronomy. Providing examples from such projects as the Square Kilometer Array (SKA), the world’s largest radio telescope that generates over an Exabyte of data every day, the book offers solutions for coping with the challenges and opportunities presented by the exponential growth of astronomical data. Presenting state-of-the-art results and research, this book is a timely reference for both practitioners and researchers working in radio astronomy, as well as students looking for a basic understanding of big data in astronomy.


ALMA Provides First Complete Image of Fomalhaut’s Debris Disk

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have made the first complete millimeter-wavelength image of the ring of dusty debris surrounding the young star Fomalhaut, and found that the ice content of colliding exocomets within it is similar to comets in our own Solar System.

Composite image of the Fomalhaut star system. The ALMA data, shown in orange, reveal the distant and eccentric debris disk in never-before-seen detail. The central dot is the unresolved emission from the star, which is about twice the mass of our Sun. Optical data from the NASA/ESA Hubble Space Telescope is in blue the dark region is a coronagraphic mask, which filtered out the otherwise overwhelming light of the central star. Image credit: ALMA / ESO / NAOJ / NRAO / M. MacGregor / NASA / ESA / Hubble / P. Kalas / B. Saxton / AUI / NSF.

Fomalhaut is a young star located in the constellation of Piscis Austrinus, approximately 25 light-years from Earth.

Also known as alpha Piscis Austrini and HD 216956, Fomalhaut is 440 million years old, or about one-tenth the age of the Solar System, and is one of only about twenty systems in which planets have been imaged directly.

Earlier ALMA observations of the star — taken in 2012 when the telescope was still under construction — revealed only about one half of the debris disk. Though that image was merely a test of ALMA’s initial capabilities, it nonetheless provided tantalizing hints about the nature and possible origin of the disk.

The new ALMA observations offer a stunningly complete view of this glowing band of debris and also suggest that there are chemical similarities between its icy contents and comets in the Solar System.

“ALMA has given us this staggeringly clear image of a fully formed debris disk,” said Dr. Meredith MacGregor, an astronomer at the Harvard-Smithsonian Center for Astrophysics and lead author on one of two papers accepted for publication in the Astrophysical Journal describing these observations.

“We can finally see the well-defined shape of the disk, which may tell us a great deal about the underlying planetary system responsible for its highly distinctive appearance.”

As revealed in the new ALMA image, a brilliant band of icy dust about 2 billion km wide has formed approximately 20 billion km from the star.

“Using the new ALMA data and detailed computer modeling, we were able to calculate the precise location, width, and geometry of the disk. These parameters confirm that such a narrow ring is likely produced through the gravitational influence of planets in the system,” said Dr. MacGregor, lead author on the team’s first paper.

The new observations are also the first to definitively show ‘apocenter glow,’ a phenomenon predicted in a 2016 paper by MIT researcher Margaret Pan, who is also a co-author on the new ALMA papers.

Like all objects with elongated orbits, the dusty material in the Fomalhaut disk travels more slowly when it is farthest from the star. As the dust slows down, it piles up, forming denser concentrations in the more distant portions of the disk. These dense regions can be seen by ALMA as brighter millimeter-wavelength emission.

Using the same ALMA dataset, but focusing on distinct millimeter-wavelength signals naturally emitted by molecules in space, the team also detected vast stores of carbon monoxide gas in precisely the same location as the debris disk.

“These data allowed us to determine that the relative abundance of carbon monoxide plus carbon dioxide around Fomalhaut is about the same as found in comets in our own Solar System,” said Dr. Luca Matrà, a researcher at the University of Cambridge and lead author on the team’s second paper.

“This chemical kinship may indicate a similarity in comet formation conditions between the outer reaches of this planetary system and our own.”

The researchers believe this gas is either released from continuous comet collisions or the result of a single, large impact between supercomets hundreds of times more massive than Hale-Bopp.

The presence of this well-defined debris disk around Fomalhaut, along with its curiously familiar chemistry, may indicate that this system is undergoing its own version of the Late Heavy Bombardment, a period approximately 4 billion years ago when the Earth and other planets were routinely struck by swarms of asteroids and comets left over from the formation of our Solar System.

Meredith A. MacGregor et al. 2017. A Complete ALMA Map of the Fomalhaut Debris Disk. ApJ, accepted for publication arXiv: 1705.05867

L. Matrà et al. 2017. Detection of exocometary CO within the 440 Myr-old Fomalhaut belt: a similar CO+CO2 ice abundance in exocomets and Solar System comets. ApJ, accepted for publication arXiv: 1705.05868


Scientific Staff

The table below lists each member of the NRAO scientific staff, their scientific interests, and functional duties at the Observatory. Phone numbers and e-mail addresses for all employees are available in the NRAO Directory.

Tenured Staff

Solar/stellar radiophysics, heliophysics Frequency Agile Solar Radio telescope (FASR) planning and development.

NRAO Director: Stellar activity, radio stars very Long baseline interferometry techniques and applications SETI astrometry and celestial frame definition space situational awareness.

High-mass star formation, astrochemistry, masers, magnetic fields, supernova remnants, small-scale structure in the interstellar medium, ALMA/NAASC, ALMA CASA subsystem scientist.

Formation of First Galaxies and cosmic reionization HI 21cm cosmology gas and dust in early galaxies Radio Galaxies NRAO Chief Scientist.

Dark energy, Hubble constant, black hole masses, nearby galaxies, evolution of star formation, radio surveys, radio emission from QSOs, supermassive black holes not in AGNs.

Extragalactic radio sources, interferometry, cosmic masers, computational techniques for data analysis, scientific support, NRAO sky surveys.

Extragalactic, multi-wavelength studies of infrared galaxies, radio galaxies and quasar hosts ALMA/NAASC, ALMA/ NAASC web pages. NRAO/UVA Joint Faculty.

ALMA Charlottesville Science Verification, CASA Scientific Steering Committee, Astrometry and Relativity Tests, VSOP and RadioAstron coordination, VLBA Spacecraft Tracking, Deep Radio Imaging.

Transient radio sky with emphasis on EM-GW.

Millimeter- and submillimeter-wave receiver development, SIS mixer design, CDL and ALMA Project.

Interstellar chemistry, diffuse clouds, galactic structure NRAO Spectrum Manager and Chair of IUCAF NAASC member specializing in the ALMA Observing Tool, proposal preparation and scheduling.

Millimeter-wave MMIC design, analog-digital-photonic integration, Integrated Receiver Development Group Leader.

Galaxy formation and evolution star formation and its associated feedback on the ISM of galaxies cosmic ray propagation and magnetic fields radio surveys next-generation VLA Project Scientist.

Cosmology, cosmic background radiation, gravitational lenses, epoch of reionization, radio synoptic sky surveys, radio transients, interferometric imaging algorithms, ALMA and VLA scientific support.

Interferometry, polarimetry, antenna and receiver metrology.

Microwave and millimeter-wave low-noise devices, amplifiers and receivers, CMBR radiometers EVLA/VLBA/GBT/ALMA receiver development.

Pulsar searches and timing (especially binary and millisecond pulsars) and applications for basic physics, such as gravitational wave detection (NANOGrav) pulsar infrastructure improvement.

Star formation, structure and chemistry of the ISM in galaxies, circumstellar material ALMA Program Scientist.

Scientists/Astronomers

Galactic structure and abundances, H II regions, planetary nebulae telescope time allocation, science data archive.

Extragalactic Astronomy Galaxy Evolution Star Formation AGN outflows Interacting Galaxies: e.g., Arp 220 Observations at Radio, Millimeter, Submillimeter and Infrared wavelengths. ALMA/NAASC: ALMA Ambassador Program. NAASC user support: ALMA Ambassadors program, face-to-face visitor program.

Studies of radio emission variability. Quasars and blazars: jet dynamic. Astrochemistry: cold cores. Stellar Astrophysics: Eta Carinae and Proto Planetary Nebulae. Masers: Halpha Recombination Lines. Radio Instrumentation: pointing, holography.

Linking Radio and Gamma-Ray emission in Blazars. HI absorption in AGN. AGN jet formation and variability. All things VLBI. Instrumentation.

Cosmic masers, active galaxies, cosmology, molecular gas in AGN, ALMA user support, Student Programs Coordinator.

Planetary astronomy transient sources Division Head, VLA/VLBA Science Support Division.

Formation and evolution of stars, planetary disks and systems. ALMA Observatory Scientist

Star formation, circumstellar disks, protostellar outflows Director of the VLA Sky Survey project.

Masers, young stellar objects, AGB stars, pre-planetary nebulae, spectropolarimetry EVLA/VLBA user programs, EVLA and VLBA scientific support EVLA commissioning VLBA/EVLA scheduling.

Rapid accretion events from low mass stars, outflow feedback in star-forming regions, debris disks and the search for young planetary systems, techniques in wide-field imaging, interferometric calibration approaches ALMA Deputy Director.

Star formation with a special interest in the role of magnetic fields.

Kinematics and dynamics of galaxies, galaxy evolution, galaxy-galaxy interactions, sub-millimeter galaxies ALMA science.

Pulsars High-precision pulsar timing and gravitational waves Interstellar scattering Polarimetry Signal processing Pulsar instrumentation and analysis software.

JVLA and VLBA science & engineering support, system tests. Radio and X-ray observations of microquasars, VLBA astrometry, spacecraft tracking.

ALMA Director massive stars colliding-wind systems stellar radio emission radio astronomy techniques.

Origin and evolution of radio galaxies the cold circum-galactic medium at high redshifts low-surface-brightness millimeter interferometry CASA User Liaison.

Dust and gas evolution in Protoplanetary and Debris Disks. Planetary Formation. Episodic Accretion in FU Ori and Ex Ori systems. Astronomical Polarimetry. ALMA: Array Calibration, Astrometry.

Extragalactic HI, galaxy evolution, merging galaxies data reduction pipelines

High-mass star formation, protoclusters, UCHII regions, hot cores, outflows, masers millimeter/submillimeter interferometry ALMA commissioning and analysis utilities CASA pipeline heuristics atmospheric calibration and antenna position determination.

(High mass) star formation, interstellar medium and molecular clouds NAASC user support, ALMA simulator and pipeline NRAO/UVA Joint Faculty.

Interstellar molecules, and astrochemisty NRAO Deputy Director and Assistant Director for North American ALMA Operations.

Radio galaxies, relativistic jets, galaxy evolution, AGN feedback, nearby star-forming galaxies, continuum radio surveys, (very) low radio frequencies, computational radio galaxy evolution EVLA/VLBA Science support, user support, student programs (Socorro).

Nearby galaxies and clusters, galaxy dynamics, VLA pipeline and VLASS, data visualization, NRAO NINE Program.

Star formation, molecular gas, dust, and magnetic fields in nearby galaxies, GBT 4mm system, ALMA pipeline development, CASA testing.

Extragalactic radio sources, quasars and luminous active galactic nuclei, high-redshift galaxies, multi-wavelength sky surveys, data reduction pipelines. VLA Sky Survey (VLASS) Operations Coordinator, VLA user support.

Sgr A* and the ISM at the Galactic centre mm/submm interferometry NAASC ALMA Scientific Software and User Support.

Quasars and active galactic nuclei, distant galaxies and galaxy evolution, extragalactic surveys. NAASC, ALMA archive and user support.

Astronomical transients, especially classical novae and fast radio bursts connections between radio and gamma-ray emission blazars and AGN VLBI physics and astronomy education.

Protoplanetary disks, astrochemistry, interferometric imaging techniques, machine learning ALMA pipeline development.

Galactic and extragalactic star formation Molecular spectroscopy of comets Antenna performance characterization Millimeter/submillimeter measurement calibration ALMA Publications of the Astronomical Society of the Pacific Editor-in-Chief.

Extragalactic star formation and evolution large radio surveys data reduction pipelines calibration and imaging techniques VLA telescope and user support VLA CASA subsystem scientist VLA sky survey science-ready data products.

Galaxy Clusters, Observational Cosmology Imaging Algorithms Instrumentation Development ALMA & GBT support team lead, NA-ALMA Scientific Software Support.

Pulsars, radio polarimetry statistics Assistant Director for New Mexico Operations ngVLA Project Director.

Nearby galaxies, outer galaxy disks. NAASC, CASA Scientific Testing Lead, ALMA Proposal Handling Team.

Astrometry of young stellar objects, novae, symbiotic stars VLBA/VLA support, VLA Scheduling Manager.

(Ultra) Luminous IR Galaxies, extragalactic HI surveys, deep continuum surveys, cm-wavelength molecular lines, OH megamasers, VLBI imaging of high-z QSOs and sub-mm galaxies, Galactic methanol masers, Zeeman effect VLA testing, VLA/VLBA Scientific User Support group lead.

ALMA Data Management Group Manager

Molecular cloud and star formation in nearby active, dwarf, and interacting galaxies multi-wavelength observations of the ISM in galaxies galaxy evolution the Galactic Center CASA Project scientist VLA user support and sub-system scientist for VLA pipeline infrastructure.

Star formation, protostellar outflows, molecular cloud evolution NAASC user support, ALMA archive.

Galaxy evolution, multi-wavelength observations of massive and dwarf galaxy mergers, dynamical modeling / N-body simulations, ALMA user support, ALMA Ambassadors.

Deputy AD, North American ALMA Operations - NA ARC Manager Astrochemistry, astrobiology, physical and chemical conditions of the interstellar, circumstellar, and cometary media.

Active Galactic Nuclei/Quasars relativistic outflows unassociated gamma-ray sources radio/gamma-ray sky connection low-frequency radio interferometry very long baseline interferometry VLA sky survey VLA/VLBA Science Support

Circumstellar masers and AGB stars centers of the Galaxy and Andromeda, interstellar masers and SNR/MC interactions data-reduction pipelines in AIPS VLA/VLBA scientific support subsystem scientist for the observing preparation tool (OPT).

Low-to-intermediate mass star formation proto-planetary disk formation multiple star formation protostellar outflows molecular clouds astrochemistry.

Deputy North American ARC Manager, ALMA Telescope Interface Group Manager Properties of the interstellar medium and star formation in galaxies using (sub)millimeter and radio observations, molecular gas in galaxies, (sub)millimeter interferometry.

Intermediate-mass black holes, massive black holes on the move next-generation VLA (ngVLA) Scientific Editor, AAS Journals.

Atomic and molecular gas in galaxies, Galaxy morphology, Bayesian statistics, Stellar dynamics, Supermassive black holes, NAASC ALMA user support and pipeline development.

Scientists/Computational Science

Supernova remnants, Galactic astronomy, Wide-band surveys, interferometric imaging and calibration algorithms, scientific computational techniques, high performance computing using multi-core CPU, GPUs and FPGAs, Algorithms research and development (ARDG)/Production scientific software development (CASA).

Low-frequency calibration and imaging, imaging algorithm development, CASA.

Radio galaxies, HI in galaxies, interstellar medium, computer analysis of astronomical data AIPS.

Polarimetry, Interferometry, Synthesis imaging algorithms, High Performance Computing, Algorithms R&D, Faraday Synthesis, Radio Deep Fields, AGN.

Polarization interferometry, VLBI, astrometry, kpc parallaxes synthesis calibration and imaging algorithms, CASA ALMA and EVLA commissioning support ALMA, EVLA and VLBA user support.

RFI mitigation, RFI localization, numerical techniques and image deconvolution. CASA (software development).

X-ray binaries, the Galactic Center, extragalactic variable radio sources, interferometric and single dish data analysis systems CASA.

Numerical techniques and high-performance computing applied to interferometric image reconstruction, calibration and RFI-removal CASA (software development), ARDG (algorithm research).

Scientists/Research Engineering

Special-purpose radio telescope systems, low-noise amplifiers, array receivers, adaptive RFI excision, advanced receiver development, Dark Ages / Epoch of Reionization science, and radio-based particle physics Low Noise Radiometer Laboratory Group Leader.

Pulsars, astrometry, interstellar scattering VLBI software correlation.

Central Development Laboratory (CDL) Director millimeter/submm/infrared/acoustic technology development, analysis and systems performance, radar characterization of physical objects, modeling of moving targets in compact cm/mm-wavelength radar ranges.

Superconducting travelling-wave kinetic-inductance parametric (TKIP) amplifiers, Millimeter- and submillimeter-wave receivers, CDL and ALMA project.

Signal processing and statistics, large-scale back-end solutions, algorithms and machine learning.

ALMA local-oscillator development, frequency-multiplier development ALMA Front-End System engineering.

Microwave and Millimeter-Wave Photonics, Coherent Local Oscillator Generation and Distribution, Phased Array Receivers

Electromagnetics, optics and antennas. Development of polarizers and broadband feeds for cm to mm-wave applications.

Emeritus Scientists

EVLA control and software development, VLA/VLBA scheduling.

Interstellar medium, molecular clouds, gravitation and dark matter.

CO, galactic structure, gas-rich galaxies, interstellar medium.

Galactic-center studies, galactic masers, pulsars, supernova remnants, nearby galaxies history of radio astronomy.

Cosmology, signal processing, phased array feed design, advanced receiver development, RFI mitigation former NRAO Chief Technologist.

Cosmology, galaxies, stellar populations former Assistant Director for Chilean Affairs and NRAO/AUI representative in Chile.

Structure of spiral galaxies, stellar winds.

Extra-galactic radio sources, quasars, cosmology, radio telescopes, history of radio astronomy NRAO Archives, space VLBI.

Starburst galaxies, ultraluminous infrared galaxies, active galactic nuclei, galaxy evolution, large scale structure, extragalactic surveys, Wide-field Infrared Survey Explorer, WISE

Evolution of galaxies, clusters of galaxies, radio galaxies, deep continuum surveys EVLA.

Superconducting millimeter--and submillimeter--wave low-noise devices, circuit and receiver development.

Extragalactic hydrogen, normal galaxies, dark matter.

Radio-astronomy instrumentation, theory and practice of radio interferometry and synthesis imaging, interference mitigation and spectrum protection for radio astronomy.

Interstellar medium, star formation, high- redshift molecular emission galaxies, galaxy formation/evolution.

Extragalactic radio sources VLBI, VLBA development, VLBA scientific support.

Jansky Fellows

Jansky Fellow at NRAO in Socorro.

Jansky Fellow at NRAO in Charlottesville. Research interests: the interstellar medium, star formation, and stellar feedback galaxy evolution radio recombination lines low-frequency calibration and spectroscopy.

Janksy Fellow at NRAO in Charlottesville. Low-frequency radio astronomy instrumentation R&D: computational electromagnetics, antenna prototype, radiometry, polarimetry, global 21-cm experiment (Cosmic Twilight Polarimeter - CTP).

Jansky Fellow at NRAO in Socorro.

Jansky Fellow at NRAO Socorro and the University of New Mexico VLBI astrometry using masers, high-mass star forming regions evolved Galactic populations Galactic structure Astrometry cross-match at infrared and optical (Gaia).

Jansky Fellow in Charlottesville.

Jansky Fellow in Socorro high-mass star and cluster formation, interstellar medium, astrochemistry, dust polarization interferometry and molecular spectroscopy.

Jansky Fellow at NRAO in Charlottesville.

Jansky Fellow at NRAO in Charlottesville. Debris disks, protoplanetary disks, FUor/EXor disks & episodic accretion radiative transfer modelling radio emission of main-sequence stars, ultracool dwarfs, and stellar atmosphere modelling.

Research Associates and NRAO Postdoctoral Fellows

Galaxy formation and evolution: structure and gas content of high-z galaxies. Active Galactic Nuclei (AGN): radio galaxies, feedback. Radio/mm interferometry: imaging and spectroscopy

NRAO Research Associate in Socorro working on ngVLA configuration studies and simulations. Early stages of high-mass star formation, ionized jets and molecular outflows, hot molecular cores, infrared dark cloud cores, ultra-compact and hyper-compact HII regions.

ALMA-JAO Postdoc in Santiago, Chile. Properties of molecular clouds, different phases of the interstellar medium and the process of star formation at different size scales in nearby galaxies and the Milky Way.

The National Radio Astronomy Observatory is a facility of the National Science Foundation
operated under cooperative agreement by Associated Universities, Inc.


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