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Full-Text Articles in Physical Sciences and Mathematics

A Mildly Relativistic Outflow From The Energentic, Fast-Rising Blue Optical Transient Css161010 In A Dwarf Galaxy, Deanne L. Coppejans, R. Margutti, G. Terreran, A. J. Nayana, E. R. Coughlin, T. Laskar, K. D. Alexander, M. Bietenholz, D. Caprioli, P. Chandra, M. R. Drout, D. Frederiks, C. Frohmaier, K. H. Hurley, C. S. Kochanek, M. Macleod, A. Meisner, P. E. Nugent, A. Ridnaia, D. J. Sand, D. Svinkin, C. Ward, S. Yang, A. Baldeschi, I. V. Chilingarian, Y. Dong, C. Esquivia, W. Fong, C. Guidorzi, P. Lundqvist, D. Milisavljevic May 2020

A Mildly Relativistic Outflow From The Energentic, Fast-Rising Blue Optical Transient Css161010 In A Dwarf Galaxy, Deanne L. Coppejans, R. Margutti, G. Terreran, A. J. Nayana, E. R. Coughlin, T. Laskar, K. D. Alexander, M. Bietenholz, D. Caprioli, P. Chandra, M. R. Drout, D. Frederiks, C. Frohmaier, K. H. Hurley, C. S. Kochanek, M. Macleod, A. Meisner, P. E. Nugent, A. Ridnaia, D. J. Sand, D. Svinkin, C. Ward, S. Yang, A. Baldeschi, I. V. Chilingarian, Y. Dong, C. Esquivia, W. Fong, C. Guidorzi, P. Lundqvist, D. Milisavljevic

Physics & Astronomy Faculty Research

We present X-ray and radio observations of the Fast Blue Optical Transient CRTS-CSS161010 J045834−081803 (CSS161010 hereafter) at t = 69–531 days. CSS161010 shows luminous X-ray (L x ~ 5 × 1039 erg s−1) and radio (L ν ~ 1029 erg s−1 Hz−1) emission. The radio emission peaked at ~100 days post-transient explosion and rapidly decayed. We interpret these observations in the context of synchrotron emission from an expanding blast wave. CSS161010 launched a mildly relativistic outflow with velocity Γβc ≥ 0.55c at ~100 days. This is faster than the non-relativistic AT 2018cow (Γβc ~ 0.1c) and closer to ZTF18abvkwla (Γβc …


The Planetary Luminosity Problem: " Missing Planets" And The Observational Consequences Of Episodi Accretion, Sean D. Brittain, Joan R. Najita, Ruobing Dong, Zhaohuan Zhu May 2020

The Planetary Luminosity Problem: " Missing Planets" And The Observational Consequences Of Episodi Accretion, Sean D. Brittain, Joan R. Najita, Ruobing Dong, Zhaohuan Zhu

Physics & Astronomy Faculty Research

The high occurrence rates of spiral arms and large central clearings in protoplanetary disks, if interpreted as signposts of giant planets, indicate that gas giants commonly form as companions to young stars (Myr) at orbital separations of 10–300 au. However, attempts to directly image this giant planet population as companions to more mature stars (>10 Myr) have yielded few successes. This discrepancy could be explained if most giant planets form by "cold start," i.e., by radiating away much of their formation energy as they assemble their mass, rendering them faint enough to elude detection at later times. In that …


Alma 0.88 Mm Survey Of Disks Around Planetary-Mass Companions, Ya-Lin Wu, Brendan P. Bowler, Patrick D. Sheehan, Sean M. Andrews, Gregory J. Herczeg, Adam L. Kraus, Luca Ricci, David J. Wilner, Zhaohuan Zhu Apr 2020

Alma 0.88 Mm Survey Of Disks Around Planetary-Mass Companions, Ya-Lin Wu, Brendan P. Bowler, Patrick D. Sheehan, Sean M. Andrews, Gregory J. Herczeg, Adam L. Kraus, Luca Ricci, David J. Wilner, Zhaohuan Zhu

Physics & Astronomy Faculty Research

Characterizing the physical properties and compositions of circumplanetary disks can provide important insights into the formation of giant planets and satellites. We report Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum observations of six planetary-mass (10–20 M Jup) companions: CT Cha b, 1RXS 1609 b, ROXs 12 b, ROXs 42B b, DH Tau b, and FU Tau b. No continuum sources are detected at the locations of the companions down to 3σ limits of 120–210 μJy. Given these nondetections, it is not clear whether disks around planetary-mass companions indeed follow the disk-flux–host-mass trend in the stellar regime. The faint …


Fast Radio Bursts From Interacting Binary Neutron Star Systems, Bing Zhang Feb 2020

Fast Radio Bursts From Interacting Binary Neutron Star Systems, Bing Zhang

Physics & Astronomy Faculty Research

Recent observations of repeating fast radio bursts (FRBs) suggest that some FRBs reside in an environment consistent with that of binary neutron star (BNS) mergers. The bursting rate for repeaters could be very high and the emission site is likely from a magnetosphere. We discuss a hypothesis of producing abundant repeating FRBs in BNS systems. Decades to centuries before a BNS system coalesces, the magnetospheres of the two neutron stars start to interact relentlessly. Abrupt magnetic reconnection accelerates particles, which emit coherent radio waves in bunches via curvature radiation. FRBs are detected as these bright radiation beams point toward Earth. …


Asteroid Belt Survival Through Stellar Evolution: Dependence On The Stellar Mass, Rebecca G. Martin, Mario Livio, Jeremy L. Smallwood, Cheng Chen Feb 2020

Asteroid Belt Survival Through Stellar Evolution: Dependence On The Stellar Mass, Rebecca G. Martin, Mario Livio, Jeremy L. Smallwood, Cheng Chen

Physics & Astronomy Faculty Research

Polluted white dwarfs are generally accreting terrestrial-like material that may originate from a debris belt like the asteroid belt in the Solar system. ... See full text for complete abstract.


An Ideal Testbed For Planet-Disk Interaction: Two Giant Protoplanets In Resonance Shaping The Pds 70 Protoplanetary Disk, Jaehan Bae, Zhaohuan Zhu, Clément Baruteau, Myriam Benisty, Cornelis P. Dullemong, Stefano Facchini, Andrea Isella, Miriam Keppler, Laura M. Pérez, Richard Teague Oct 2019

An Ideal Testbed For Planet-Disk Interaction: Two Giant Protoplanets In Resonance Shaping The Pds 70 Protoplanetary Disk, Jaehan Bae, Zhaohuan Zhu, Clément Baruteau, Myriam Benisty, Cornelis P. Dullemong, Stefano Facchini, Andrea Isella, Miriam Keppler, Laura M. Pérez, Richard Teague

Physics & Astronomy Faculty Research

While numerical simulations have been playing a key role in the studies of planet–disk interaction, testing numerical results against observations has been limited so far. With the two directly imaged protoplanets embedded in its circumstellar disk, PDS 70 offers an ideal testbed for planet–disk interaction studies. Using two-dimensional hydrodynamic simulations we show that the observed features can be well explained with the two planets in formation, providing strong evidence that previously proposed theories of planet–disk interaction are in action, including resonant migration, particle trapping, size segregation, and filtration. Our simulations suggest that the two planets are likely in 2:1 mean …


Photoionization Calculations Of The Radiation Force Due To Spectral Lines In Agns, Randall C. Dannen, Daniel Proga, Timothy R. Kallman, Tim Waters Sep 2019

Photoionization Calculations Of The Radiation Force Due To Spectral Lines In Agns, Randall C. Dannen, Daniel Proga, Timothy R. Kallman, Tim Waters

Physics & Astronomy Faculty Research

One of the main mechanisms that could drive mass outflows in active galactic nuclei (AGNs) is radiation pressure due to spectral lines. Although straightforward to understand, the actual magnitude of the radiation force is challenging to compute because the force depends on the physical conditions in the gas, as well as the strength, spectral energy distribution (SED), and geometry of the radiation field. We present results from our photoionization and radiation transfer calculations of the force multiplier, M(ξ, t), using the same radiation field to compute the gas photoionization and thermal balance. We assume low gas density (n = 104 …


Multiple Spiral Arms In The Disk Around Intermediate-Mass Binary Hd 34700a, John D. Monnier, Tim Harries, Jaehan Bae, Benjamin R. Setterholm, Anna Laws, Alicia Aarnio, Fred C. Adams, Sean Andrews, Nuria Calvet, Catherine Espaillat, Lee Hartmann, Stefan Kraus, Melissa Mcclure, Chris Miller, Rebecca Oppenheimer, David Wilner, Zhaohuan Zhu Feb 2019

Multiple Spiral Arms In The Disk Around Intermediate-Mass Binary Hd 34700a, John D. Monnier, Tim Harries, Jaehan Bae, Benjamin R. Setterholm, Anna Laws, Alicia Aarnio, Fred C. Adams, Sean Andrews, Nuria Calvet, Catherine Espaillat, Lee Hartmann, Stefan Kraus, Melissa Mcclure, Chris Miller, Rebecca Oppenheimer, David Wilner, Zhaohuan Zhu

Physics & Astronomy Faculty Research

We present the first images of the transition disk around the close binary system HD 34700A in polarized scattered light using the Gemini Planet Imager instrument on Gemini South. The J and H band images reveal multiple spiral-arm structures outside a large (R = 0.49" = 175 au) cavity along with a bluish spiral structure inside the cavity. The cavity wall shows a strong discontinuity and we clearly see significant non-azimuthal polarization Uphi consistent with multiple scattering within a disk at an inferred inclination ~42deg. Radiative transfer modeling along with a new Gaia distance suggest HD 37400A is a young …