Search Publications
VIA MACHINAE 2.0: Full-sky, model-agnostic search for stellar streams in Gaia DR2
Buckley, Matthew R.; Shih, David; Necib, Lina
We present an update to VIA MACHINAE, an automated stellar stream-finding algorithm based on the deep learning anomaly detector ANODE. VIA MACHINAE identifies stellar streams within Gaia, using only angular positions, proper motions, and photometry, without reference to a model of the Milky Way potential for orbit integration or stellar distances.…
The morphological mix of dwarf galaxies in the nearby Universe
Kaviraj, S.; Watkins, A. E.; Lazar, I. +3 more
We use a complete, unbiased sample of 257 dwarf (10$^{8}\, {\rm M}_{\odot } \lt M_{\rm {\star }} \lt 10^{9.5}\, {\rm M}_{\odot }$) galaxies at z < 0.08, in the COSMOS field, to study the morphological mix of the dwarf population in low-density environments. Visual inspection of extremely deep optical images and their unsharp-masked counterparts…
The Heavy Metal Survey: Star Formation Constraints and Dynamical Masses of 21 Massive Quiescent Galaxies at z = 1.3–2.3
Barro, Guillermo; Franx, Marijn; van Dokkum, Pieter +14 more
In this paper, we present the Heavy Metal Survey, which obtained ultradeep medium-resolution spectra of 21 massive quiescent galaxies at 1.3 < z < 2.3 with Keck/LRIS and MOSFIRE. With integration times of up to 16 hr per band per galaxy, we observe numerous Balmer and metal absorption lines in atmospheric windows. We successfully derive spec…
Abundances of iron-peak elements in accreted and in situ born Galactic halo stars
Skúladóttir, Á.; Amarsi, A. M.; Nissen, P. E. +1 more
Context. Studies of the element abundances and kinematics of stars belonging to the Galactic halo have revealed the existence of two distinct populations: accreted stars with a low [α/Fe] ratio and in situ born stars with a higher ratio.
Aims: Previous work on the abundances of C, O, Na, Mg, Si, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in high-α an…
Possible Carbon Dioxide above the Thick Aerosols of GJ 1214 b
Fortney, Jonathan J.; Wheatley, Peter J.; Henry, Gregory W. +14 more
Sub-Neptune planets with radii smaller than Neptune (3.9 R ⊕) are the most common type of planet known to exist in the Milky Way, even though they are absent in the solar system. These planets can potentially have a large diversity of compositions as a result of different mixtures of rocky material, icy material, and gas accreted from a…
Extended Stellar Populations in Ultrafaint Dwarf Galaxies
Vivas, A. Katherina; Martínez-Vázquez, Clara E.; Tau, Elisa A.
The possible existence of stellar halos in low-mass galaxies is being intensely discussed nowadays after some recent discoveries of stars located in the outskirts of dwarf galaxies of the Local Group. RR Lyrae stars can be used to identify the extent of these structures, taking advantage of the minimization of foreground contamination they provide…
Characterizing the Average Interstellar Medium Conditions of Galaxies at z ∼ 5.6–9 with Ultraviolet and Optical Nebular Lines
Papovich, Casey; Cole, Justin W.; Finkelstein, Steven L. +30 more
Ultraviolet (UV; rest-frame ∼1200–2000 Å) spectra provide a wealth of diagnostics to characterize fundamental galaxy properties, such as their chemical enrichment, the nature of their stellar populations, and their amount of Lyman-continuum (LyC) radiation. In this work, we leverage publicly released JWST data to construct the rest-frame UV-to-opt…
Multimass modelling of milky way globular clusters - II. Present-day black hole populations
Hénault-Brunet, V.; Gieles, M.; Baumgardt, H. +2 more
Populations of stellar-mass black holes (BHs) in globular clusters (GCs) influence their dynamical evolution and have important implications on one of the main formation channels for gravitational wave sources. Inferring the size of these populations remains difficult, however. In this work, multimass models of 34 Milky Way GCs, first presented in…
The Search for Failed Supernovae with the Large Binocular Telescope: The Mid-infrared Counterpart to N6946-BH1
Kochanek, Christopher S.; Neustadt, Jack M. M.; Stanek, Krzysztof Z.
We present JWST MIRI 5.6, 10, and 21 µm observations of the candidate failed supernova N6946-BH1 along with Hubble Space Telescope (HST) WFPC/IR 1.1 and 1.6 µm data and ongoing optical monitoring data with the Large Binocular Telescope. There is a very red, dusty source at the location of the candidate, which has only ∼10%–15% of the l…
Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter
Gong, Yan; Chen, Xuelei; Lin, Hengjie +1 more
A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope (JWST), and it may require a high star formation efficiency. However, this will lead to large number density of ionizing photons in the epoch of reionization (EoR), so that the reionization history will be…