Search Publications
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. I. Precise Distances, Masses, Ages, and 3D Velocities of ∼140,000 Red Clump Stars
Wu, Yaqian; Xiang, Maosheng; Huang, Yang +10 more
We present a sample of ∼140,000 primary red clump (RC) stars of spectral signal-to-noise ratios higher than 20 from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Galactic spectroscopic surveys, selected based on their positions in the metallicity-dependent effective temperature-surface gravity and color-metallicity diagram…
The growth of brightest cluster galaxies and intracluster light over the past 10 billion years
Donahue, Megan; Mulchaey, John S.; Connor, Thomas +9 more
We constrain the evolution of the brightest cluster galaxy plus intracluster light (BCG + ICL) using an ensemble of 42 galaxy groups and clusters that span redshifts of z = 0.05-1.75 and masses of M500,c= 2 × 1013-1015 M⊙. Specifically, we measure the relationship between the BCG + ICL stellar mass M
Candidate Population III stellar complex at z = 6.629 in the MUSE Deep Lensed Field
Treu, T.; Castellano, M.; Pentericci, L. +20 more
We discovered a strongly lensed (µ ≳ 40) Ly α emission at z = 6.629 (S/N ≃ 18) in the MUSE Deep Lensed Field (MDLF) targeting the Hubble Frontier Field (HFF) galaxy cluster MACS J0416. Dedicated lensing simulations imply that the Ly α emitting region necessarily crosses the caustic. The arc-like shape of the Ly α extends 3 arcsec on the obse…
Revisiting MOA 2013-BLG-220L: A Solar-type Star with a Cold Super-Jupiter Companion
Cole, Andrew A.; Beaulieu, Jean-Philippe; Bond, Ian A. +7 more
We present the analysis of high-resolution images of MOA-2013-BLG-220, taken with the Keck adaptive optics system six years after the initial observation, identifying the lens as a solar-type star hosting a super-Jupiter-mass planet. The masses of planets and host stars discovered by microlensing are often not determined from light-curve data, whi…
Age demographics of the Milky Way disc and bulge
Evans, N. W.; Belokurov, V.; Grady, J.
We exploit the extensive Gaia Data Release 2 set of long-period variables to select a sample of O-rich Miras throughout the Milky Way disc and bulge for study. Exploiting the relation between Mira pulsation period and stellar age/chemistry, we slice the stellar density of the Galactic disc and bulge as a function of period. We find that the morpho…
Gamma-Ray Urgent Archiver for Novel Opportunities (GUANO): Swift/BAT Event Data Dumps on Demand to Enable Sensitive Subthreshold GRB Searches
Cenko, S. Bradley; Palmer, David M.; Barthelmy, Scott +3 more
We introduce a new capability of the Neil Gehrels Swift Observatory to provide event-level data from the Burst Alert Telescope (BAT) on demand in response to transients detected by other instruments. We show that the availability of these data can effectively increase the rate of detections and arcminute localizations of gamma-ray bursts (GRB) lik…
Galaxy Morphology Network: A Convolutional Neural Network Used to Study Morphology and Quenching in ∼100,000 SDSS and ∼20,000 CANDELS Galaxies
Schawinski, Kevin; Urry, C. Megan; Powell, Meredith C. +3 more
We examine morphology-separated color-mass diagrams to study the quenching of star formation in ∼100,000 (z ∼ 0) Sloan Digital Sky Survey (SDSS) and ∼20,000 (z ∼ 1) Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) galaxies. To classify galaxies morphologically, we developed Galaxy Morphology Network (GAMORNET), a convolutio…
Primordial black holes and gravitational waves in nonstandard cosmologies
Mohanty, Subhendra; Parashari, Priyank; Bhattacharya, Sukannya
For primordial black holes (PBHs) to form a considerable fraction of cold dark matter, the required amplitude of primordial scalar perturbations is quite large (Pζ(k )∼10-2) if PBH is formed in radiation epoch. In alternate cosmological histories, where additional epoch of arbitrary equation of state precede radiation epoch, …
Detection of PAH Absorption and Determination of the Mid-infrared Diffuse Interstellar Extinction Curve from the Sight Line toward Cyg OB2-12
Draine, B. T.; Hensley, Brandon S.
The sight line toward the luminous blue hypergiant Cyg OB2-12 is widely used to study interstellar dust on account of its large extinction (AV ≃ 10 mag) and the fact that this extinction appears to be dominated by dust typical of the diffuse interstellar medium. We present a new analysis of archival Infrared Space Observatory Short Wave…
The Tidal Disruption Event AT 2018hyz II: Light-curve modelling of a partially disrupted star
Eftekhari, Tarraneh; Berger, Edo; Chornock, Ryan +18 more
AT 2018hyz (= ASASSN-18zj) is a tidal disruption event (TDE) located in the nucleus of a quiescent E+A galaxy at a redshift of z = 0.04573, first detected by the All-Sky Automated Survey for Supernovae (ASAS-SN). We present optical+UV photometry of the transient, as well as an X-ray spectrum and radio upper limits. The bolometric light curve of AT…