Search Publications
Nearly all the sky is covered by Lyman-α emission around high-redshift galaxies
Inami, H.; Steinmetz, M.; Richard, J. +22 more
Galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. Absorption-line measurements along the lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the starlight seen in galaxies, but v…
Deep Learning Based Solar Flare Forecasting Model. I. Results for Line-of-sight Magnetograms
Xu, Long; Huang, Xin; Wang, Huaning +3 more
Solar flares originate from the release of the energy stored in the magnetic field of solar active regions, the triggering mechanism for these flares, however, remains unknown. For this reason, the conventional solar flare forecast is essentially based on the statistic relationship between solar flares and measures extracted from observational dat…
The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). IV. Free-Free Emission from Protostars: Links to Infrared Properties, Outflow Tracers, and Protostellar Disk Masses
Dunham, Michael M.; Kratter, Kaitlin M.; Li, Zhi-Yun +11 more
Emission from protostars at centimeter radio wavelengths has been shown to trace the free-free emission arising from ionizing shocks as a result of jets and outflows driven by protostars. Therefore, measuring properties of protostars at radio frequencies can provide valuable insights into the nature of their outflows and jets. We present a C-band …
The Opacity of the Intergalactic Medium Measured along Quasar Sightlines at z ∼ 6
Hennawi, Joseph F.; Davies, Frederick B.; Eilers, Anna-Christina
We publicly release a new sample of 34 medium resolution quasar spectra at 5.77 ≤ z em ≤ 6.54 observed with the Echellette Spectrograph and Imager on the Keck telescope. This quasar sample represents an ideal laboratory to study the intergalactic medium (IGM) during the end stages of the epoch of reionization, and constrain the timing a…
Light Curves of Hydrogen-poor Superluminous Supernovae from the Palomar Transient Factory
Cenko, S. B.; Sollerman, J.; Spyromilio, J. +24 more
We investigate the light-curve properties of a sample of 26 spectroscopically confirmed hydrogen-poor superluminous supernovae (SLSNe-I) in the Palomar Transient Factory survey. These events are brighter than SNe Ib/c and SNe Ic-BL, on average, by about 4 and 2 mag, respectively. The peak absolute magnitudes of SLSNe-I in rest-frame g band span -2…
Gaia Data Release 2. Processing of the photometric data
Jordi, C.; Evans, D. W.; van Leeuwen, F. +13 more
Context. The second Gaia data release is based on 22 months of mission data with an average of 0.9 billion individual CCD observations per day. A data volume of this size and granularity requires a robust and reliable but still flexible system to achieve the demanding accuracy and precision constraints that Gaia is capable of delivering.
Aims…
Measuring Radial Orbit Migration in the Galactic Disk
Ting, Yuan-Sen; Hogg, David W.; Rix, Hans-Walter +2 more
We develop and apply a model to quantify the global efficiency of radial orbit migration among stars in the Milky Way disk. This model parameterizes the possible star formation and enrichment histories and radial birth profiles, and combines them with a migration model that relates present-day orbital radii to birth radii through a Gaussian probab…
The Habitability of Proxima Centauri b: Environmental States and Observational Discriminants
Lustig-Yaeger, Jacob; Meadows, Victoria S.; Arney, Giada N. +11 more
Proxima Centauri b provides an unprecedented opportunity to understand the evolution and nature of terrestrial planets orbiting M dwarfs. Although Proxima Cen b orbits within its star's habitable zone, multiple plausible evolutionary paths could have generated different environments that may or may not be habitable. Here, we use 1-D coupled climat…
Violation of the equivalence principle from light scalar dark matter
Wolf, Peter; Hees, Aurélien; Minazzoli, Olivier +2 more
In this paper, we study the local observational consequences of a violation of the Einstein equivalence principle induced by models of light scalar dark matter (DM). We focus on two different models where the scalar field couples linearly or quadratically to the standard model of matter fields. For both these cases, we derive the solutions of the …
Evidence for Pulsar-like Emission Components in the Broadband ULX Sample
Harrison, F. A.; Stern, D.; Fabian, A. C. +7 more
We present broadband X-ray analyses of a sample of bright ultraluminous X-ray sources (ULX) with the goal of investigating the spectral similarity of this population to the known ULX pulsars, M82 X-2, NGC 7793 P13, and NGC 5907 ULX. We perform a phase-resolved analysis of the broadband XMM-Newton+NuSTAR data set of NGC 5907 ULX, finding that the p…