Search Publications
Chemical Cartography with APOGEE: Mapping Disk Populations with a 2-process Model and Residual Abundances
Bizyaev, Dmitry; Pan, Kaike; Schneider, Donald P. +33 more
We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2. Building on recent work, we fit median abundance ratio trends [X/Mg] versus [Mg/H] with a 2-process model, which decomposes abundance patterns into a "prompt" component tracing core-collaps…
Gas Disk Sizes from CO Line Observations: A Test of Angular Momentum Evolution
Wilner, David J.; Tabone, Benoît; Andrews, Sean M. +7 more
The size of a disk encodes important information about its evolution. Combining new Submillimeter Array observations with archival Atacama Large Millimeter/submillimeter Array data, we analyze millimeter continuum and CO emission line sizes for a sample of 44 protoplanetary disks around stars with masses of 0.15-2 M ⊙ in several nearby …
Cosmological Results from the RAISIN Survey: Using Type Ia Supernovae in the Near Infrared as a Novel Path to Measure the Dark Energy Equation of State
Kirshner, R. P.; Smith, M.; Nichol, R. C. +26 more
Type Ia supernovae (SNe Ia) are more precise standardizable candles when measured in the near-infrared (NIR) than in the optical. With this motivation, from 2012 to 2017 we embarked on the RAISIN program with the Hubble Space Telescope (HST) to obtain rest-frame NIR light curves for a cosmologically distant sample of 37 SNe Ia (0.2 ≲ z ≲ 0.6) disc…
Inference of the cosmic rest-frame from supernovae Ia
Horstmann, Nick; Pietschke, Yannic; Schwarz, Dominik J.
We determine the proper motion of the Solar System from the Pantheon sample of type Ia supernovae (SNe). The posterior distribution of the Solar System proper velocity, its direction, and relevant cosmological parameters were obtained based on the observed distance moduli, heliocentric redshifts, and positions of SNe by means of a Markov chain Mon…
A deep survey of short GRB host galaxies over z 0-2: implications for offsets, redshifts, and environments
Troja, E.; Cenko, S. B.; Sakamoto, T. +10 more
A significant fraction (30 per cent) of well-localized short gamma-ray bursts (sGRBs) lack a coincident host galaxy. This leads to two main scenarios: (i) that the progenitor system merged outside of the visible light of its host, or (ii) that the sGRB resided within a faint and distant galaxy that was not detected by follow-up observations. Discr…
ALMA 200 pc Imaging of a z 7 Quasar Reveals a Compact, Disk-like Host Galaxy
Carilli, Chris; Fan, Xiaohui; Neeleman, Marcel +10 more
We present 0.″035 resolution (~200 pc) imaging of the 158 µm [C II] line and the underlying dust continuum of the z = 6.9 quasar J234833.34-305410.0. The 18 hour Atacama Large Millimeter/submillimeter Array observations reveal extremely compact emission (diameter ~1 kpc) that is consistent with a simple, almost face-on, rotation-supported di…
A 5 per cent measurement of the Hubble-Lemaître constant from Type II supernovae
Zheng, W.; Galbany, L.; Filippenko, A. V. +4 more
The most stringent local measurement of the Hubble-Lemaître constant from Cepheid-calibrated Type Ia supernovae (SNe Ia) differs from the value inferred via the cosmic microwave background radiation (Planck+ΛCDM) by ~5σ. This so-called Hubble tension has been confirmed by other independent methods, and thus does not appear to be a possible consequ…
An estimation of the Gaia EDR3 parallax bias from stellar clusters and Magellanic Clouds data
Maíz Apellániz, J.
Context. The early-third Gaia data release (EDR3) parallaxes constitute the most detailed and accurate dataset that currently can be used to determine stellar distances in the solar neighborhood. Nevertheless, there is still room for improvement in their calibration and systematic effects can be further reduced in some circumstances.
Aims: Th…
A stellar stream remnant of a globular cluster below the metallicity floor
Mucciarelli, Alessio; Fouesneau, Morgan; Sestito, Federico +23 more
Stellar ejecta gradually enrich the gas out of which subsequent stars form, making the least chemically enriched stellar systems direct fossils of structures formed in the early Universe1. Although a few hundred stars with metal content below 1,000th of the solar iron content are known in the Galaxy2-4, none of them inhabit g…
The effect of returning radiation on relativistic reflection
Reynolds, C. S.; Dauser, T.; Wilms, J. +5 more
We study the effect of returning radiation on the shape of the X-ray reflection spectrum in the case of thin accretion discs. We show that the returning radiation mainly influences the observed reflection spectrum for a large black hole spin (a > 0.9) and a compact primary source of radiation close to the black hole at height h < 5rg