activity
20202026
most citedMetallicity Distribution Functions of 13 Ultra-Faint Dwarf Galaxy Candidates from Hubble Space Telescope Narrowband Imaging

34 citations · 144 across the 24 of their papers we have counts for

collaborators

27 papers

astro-ph.GA2026

The Binary Fraction of Milky Way Field Stars in DESI: Dependence on Chemical Abundance

Tian Qiu, Wenting Wang, Sergey E. Koposov +39

Binary populations encode information about the physical conditions of star formation and the subsequent evolution of stellar populations. Adopting a statistical method based on mu…

astro-ph.GA2026

From observing strategies to velocity dispersion bias: forward modeling unresolved binaries in ultra-faint dwarf galaxies

Xiaowei Ou, Andrew B. Pace, Nitya Kallivayalil +9

Ultra-faint dwarf galaxies (UFDs) in the Milky Way are ideal probes of low-mass galaxy formation and dark matter because they are highly dark-matter dominated. In the lowest-mass s…

astro-ph.GA2026

Boötes III is a Tidally Disrupting Ultra-Faint Dwarf Galaxy on an Eccentric Polar Orbit

Ting S. Li, Denis Erkal, Andrew B. Pace +20

We present updated systemic properties of the ultra-faint dwarf galaxy Boötes III from the Southern Stellar Stream Spectroscopic Survey (S). We identify 21 high-probability mem…

astro-ph.GA2026

Dark Matter in Draco and Boötes I: Hints of a Core in an Ultra-Faint Dwarf from Simulation-Based Inference

Tri Nguyen, Lina Necib, Ting S. Li +8

The density profiles of dwarf spheroidal galaxies are among the most sensitive probes of dark matter physics, yet extracting them from noisy stellar kinematics remains a fundamenta…

astro-ph.GA2026

Constraining the Galactic bar using the M92 stellar stream

Amanda Byström, Sergey E. Koposov, Ting. S. Li +42

Stellar streams are excellent probes of the gravitational potential in which they evolve. In the Milky Way (MW), globular cluster (GC) streams are routinely used to infer propertie…

astro-ph.GA2026

Characterizing the GD-1 Stream with DESI DR2 Data: Thin Stream and Hot Cocoon

Emma Jarvis, Ting S. Li, Sergey E. Koposov +54

GD-1 is among the longest, coldest stellar streams in the Milky Way, making it an ideal target for probing dark matter substructure through dynamical heating. We present a catalog…

astro-ph.GA2026

The Kinematically Hot, Extremely Metal-Poor C-19 Stellar Stream in DESI DR2

Nasser Mohammed, Joseph Y. Tang, Ting S. Li +47

Stellar streams are the result of a host galaxy's gravitational potential tidally disrupting satellite dwarf galaxies and globular clusters (GCs), causing them to grow leading and…

astro-ph.GA2026

It's a matter of time: Empirical Constraints on Supernova Yields and Delay Times from Dwarf Spheroidal Galaxies

Mairéad E. Heiger, Alexander P. Ji, Joshua S. Speagle +6

The chemical abundances of a stellar population encode information about nucleosynthesis and its astrophysical sites, but this information is confounded by the specific star format…

astro-ph.GA2026

Signatures of a Tidally Induced Spiral Arm at the Anticenter of the Milky Way and a Kinematically Extended Anticenter Stream Using DESI DR2

Mika Lambert, Constance M. Rockosi, Sergey E. Koposov +46

Using the Dark Energy Spectroscopic Instrument Milky Way Survey (DESI MWS), we examine the 6D space of the anticenter region of the stellar disk (150 Galactic longitude…

astro-ph.SR2025★ 2 cited

The Binary Fraction of Stars in the Dwarf Galaxy Ursa Minor via Dark Energy Spectroscopic Instrument

Tian Qiu, Wenting Wang, Sergey Koposov +45

We utilize multi-epoch line-of-sight velocity measurements from the Milky Way Survey of the Dark Energy Spectroscopic Instrument to estimate the binary fraction for member stars in…

astro-ph.GA2025

The Milky Way stellar halo is twisted and doubly broken: insights from DESI DR2 Milky Way Survey observation

Songting Li, Wenting Wang, Sergey E. Koposov +45

Using K giants from the second data release (DR2) of the Dark Energy Spectroscopic Instrument (DESI) Milky Way (MW) Survey, we measure the shape, orientation, radial profile, and d…

astro-ph.GA2025

The Draco Dwarf Spheroidal Galaxy in the First Year of DESI Data

J. Ding, C. Rockosi, Ting S. Li +40

We investigate the spatial distribution, kinematics, and metallicity of stars in the Draco dwarf spheroidal galaxy using data from the Dark Energy Spectroscopic Instrument (DESI).…

astro-ph.GA2025★ 1 cited

Chemodynamics of BoötesI with : Revised Velocity Gradient, Dark Matter Density, and Galactic Chemical Evolution Constraints

Nathan R. Sandford, Ting S. Li, Sergey E. Koposov +14

We combine new spectroscopic observations of the ultra faint dwarf galaxy (UFD) Boötes I (Boo I) from the Southern Stellar Stream Spectroscopic Survey () with 15 years…

astro-ph.GA2025★ 1 cited

The mass of the Milky Way from outer halo stars measured by DESI DR1

Gustavo E. Medina, Ting S. Li, Gwendolyn M. Eadie +50

As a benchmark for galaxy evolution and dark matter studies, the total mass of the Milky Way is a parameter of cosmological significance, and its value at large radii from the Gala…

astro-ph.GA2025★ 12 cited

DESI Data Release 1: Stellar Catalogue

Sergey E. Koposov, Ting S. Li, C. Allende Prieto +65

In this paper we present the stellar Value-Added Catalogue (VAC) based on the DESI Data Release 1. This VAC contains stellar parameter, abundance and radial velocity measurements f…

astro-ph.GA2025

SN 2023ixf in the Pinwheel Galaxy M101: From Shock Breakout to the Nebular Phase

Weikang Zheng, Luc Dessart, Alexei V. Filippenko +39

We present photometric and spectroscopic observations of SN 2023ixf covering from day one to 442 days after explosion. SN 2023ixf reached a peak -band absolute magnitude of $-18…

astro-ph.GA2024

Modeling the Ages and Chemical Abundances of Elliptical Galaxies

Nicole Marcelina Gountanis, David H. Weinberg, Aliza G. Beverage +3

Spectroscopic studies of elliptical galaxies show that their stellar population ages, mean metallicity, and -enhancement traced by [Mg/Fe] all increase with galaxy stellar mass…

astro-ph.GA2024

Stellar Metallicities and Gradients in the Faint M31 Satellites Andromeda XVI and Andromeda XXVIII

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +11

We present stellar metallicity measurements in two faint M31 dwarf galaxies, Andromeda XVI () and Andromeda XXVIII () derived using metallicity-se…

astro-ph.GA2023

Stellar Metallicities and Gradients in the Isolated, Quenched Low-Mass Galaxy Tucana

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +10

We measure the metallicities of 374 red giant branch (RGB) stars in the isolated, quenched dwarf galaxy Tucana using Hubble Space Telescope (HST) narrow-band (F395N) Calcium H & K…

astro-ph.GA2023★ 34 cited

Metallicity Distribution Functions of 13 Ultra-Faint Dwarf Galaxy Candidates from Hubble Space Telescope Narrowband Imaging

Sal Wanying Fu, Daniel R. Weisz, Else Starkenburg +10

We present uniformly measured stellar metallicities for 463 stars in 13 Milky Way (MW) ultra-faint dwarf galaxies (UFDs; to ) using narrowband CaHK (F395N) imagi…

astro-ph.HE2023★ 7 cited

SN 2023ixf in Messier 101: Photo-ionization of Dense, Close-in Circumstellar Material in a Nearby Type II Supernova

W. V. Jacobson-Galan, L. Dessart, R. Margutti +65

We present UV/optical observations and models of supernova (SN) 2023ixf, a type II SN located in Messier 101 at 6.9 Mpc. Early-time ("flash") spectroscopy of SN 2023ixf, obtained p…

astro-ph.SR2023★ 6 cited

Validating Stellar Abundance Measurements from Multi-Resolution Spectroscopy

Nathan R. Sandford, Daniel R. Weisz, Yuan-Sen Ting

Large-scale surveys will provide spectroscopy for 50 million resolved stars in the Milky Way and Local Group. However, these data will have a high degree of heterogeneity and…

astro-ph.GA2023★ 27 cited

From Carbon to Cobalt: Chemical compositions and ages of quiescent galaxies

Aliza G. Beverage, Mariska Kriek, Charlie Conroy +5

We present elemental abundance patterns (C, N, Mg, Si, Ca, Ti, V, Cr, Fe, Co, and Ni) for a population of 135 massive quiescent galaxies at with ultra-deep rest-frame op…

astro-ph.SR2022★ 17 cited

A Panchromatic Study of Massive Stars in the Extremely Metal-Poor Local Group Dwarf Galaxy Leo A

Maude Gull, Daniel R. Weisz, Peter Senchyna +17

We characterize massive stars (M>8 M_sun) in the nearby (D~0.8 Mpc) extremely metal-poor (Z~5% Z_sun) galaxy Leo A using Hubble Space Telescope ultra-violet (UV), optical, and near…