Astrophysics Science Division
The Astrophysics Science Division conducts a broad program of research in astronomy, astrophysics, and fundamental physics. Individual investigations address issues such as the nature of dark matter and dark energy, which planets outside our solar system may harbor life, and the nature of space, time, and matter at the edges of black holes.
Early Career Scientist Spotlights
Early Career Scientist Spotlight ("ECSS") articles showcase the early career scientists
working at NASA Goddard Space Flight Center. Learn a bit about some of the wonderful
and interesting people working at Goddard!
working at NASA Goddard Space Flight Center. Learn a bit about some of the wonderful
and interesting people working at Goddard!
Latest Science Nugget
Swift Studies Gas-Churning Monster Black Holes
Latest Science Nugget
Webb Reveals Unusual Jets of Volatile Gas from Icy Centaur 29P
Latest Science Nuggets
Check out this weeks science nuggets: Astronomers Catch Unprecedented Features at Brink of Active Black Hole
Latest Science Nuggets
Check out this weeks science nuggets: Astronomers Catch Unprecedented Features at Brink of Active Black Hole
Astrophysics Science Division
The Astrophysics Science Division conducts a broad program of research in astronomy, astrophysics, and fundamental physics. Individual investigations address issues such as the nature of dark matter and dark energy, which planets outside our solar system may harbor life, and the nature of space, time, and matter at the edges of black holes.
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Organization Overview
Early Career Scientist Spotlights
Latest Science Nugget
Latest Science Nugget
Latest Science Nuggets
Tuesday, May 06, 2025
03:30 PM - 05:00 PM
ASD Colloquium Series
The Formation and Evolution of Supermassive Black Holes in the Early Universe
Nico Cappelluti (University of Miami)
The formation of supermassive black holes (SMBHs) in the first billion years after the Big Bang remains a fundamental question in astrophysics. I will review current theoretical models of SMBH seeding, including both light and heavy seed scenarios, and explore how the redshift evolution of AGN obscuration can inform our understanding of early black hole growth. I will discuss observational constraints from the AGN luminosity function and emphasize the potential of future X-ray missions—particularly the proposed AXIS probe—to resolve faint AGN populations and extend measurements to higher redshifts. I will also present recent results on the cross-power spectrum between the cosmic infrared background (CIB) and the cosmic X-ray background (CXB), based on data from Spitzer, JWST, and Chandra, which offer a direct evidence of early accreting black holes. Finally, I will consider the possibility that primordial black holes (PBHs) may play a role in seeding SMBHs, providing an alternative pathway for their rapid growth.
Read more about this event Nico Cappelluti (University of Miami)
The formation of supermassive black holes (SMBHs) in the first billion years after the Big Bang remains a fundamental question in astrophysics. I will review current theoretical models of SMBH seeding, including both light and heavy seed scenarios, and explore how the redshift evolution of AGN obscuration can inform our understanding of early black hole growth. I will discuss observational constraints from the AGN luminosity function and emphasize the potential of future X-ray missions—particularly the proposed AXIS probe—to resolve faint AGN populations and extend measurements to higher redshifts. I will also present recent results on the cross-power spectrum between the cosmic infrared background (CIB) and the cosmic X-ray background (CXB), based on data from Spitzer, JWST, and Chandra, which offer a direct evidence of early accreting black holes. Finally, I will consider the possibility that primordial black holes (PBHs) may play a role in seeding SMBHs, providing an alternative pathway for their rapid growth.
Thursday, May 08, 2025
12:00 PM - 01:00 PM
SED Director’s Seminar
Please join us for the SED Director’s Seminar. Hosted by the Exoplanets and Stellar Astrophysics Laboratory, Code 667!
Read more about this event Tuesday, May 13, 2025
03:30 PM - 05:00 PM
ASD Colloquium Series
Local Dwarf Galaxies as Laboratories to Understand Massive Stars and the ISM in the Early Universe
Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
Read more about this event Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
Tuesday, May 20, 2025
03:30 PM - 05:00 PM
ASD Colloquium Series
Local Dwarf Galaxies as Laboratories to Understand Massive Stars and the ISM in the Early Universe
Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
Read more about this event Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
Tuesday, May 27, 2025
03:30 PM - 05:00 PM
ASD Colloquium Series
Local Dwarf Galaxies as Laboratories to Understand Massive Stars and the ISM in the Early Universe
Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
Read more about this event Grace Telford (Princeton University)
Feedback from low-metallicity massive stars regulates the evolution of both dwarf and high-redshift galaxies. To understand those processes requires robust models of the metal-poor ISM in which stars form and of massive stars' winds and ionizing spectra. Yet, these models remain entirely theoretical and uncertain due to a lack of observational constraints in the extremely low-metallicity regime. In this talk, I will present a suite of JWST, HST, and Keck observations of the nearby 3% Solar metallicity galaxy Leo P. First, I will describe novel constraints on the wind properties and ionizing spectrum of the galaxy's only O-type star from modeling HST/COS and Keck/KCWI spectroscopy. This star is part of the Treasury of Extremely Metal-Poor O Stars (TEMPOS), a Large Treasury HST program that will extend this initial analysis to a much larger sample at ~5-10% Solar metallicity. I will then present new JWST/MIRI-MRS observations of Leo P, which enabled the first detection of cold molecular hydrogen at such low metallicity via rotationally excited emission from the photodissociation region illuminated by the O star. Our detailed understanding of that star's UV radiation from the HST data constrains the temperature and mass of the detected molecular hydrogen, providing a benchmark for models of the ISM at the very low metallicities typical at high redshift. Leo P showcases the potential of the metal-poor dwarf galaxies in our backyard to inform models of early galaxies.
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