128 citations · 524 across the 23 of their papers we have counts for
23 papers
The SPHEREx Ices Investigation: An Overview
Gary J. Melnick, Joseph L. Hora, Matthew L. N. Ashby +26
SPHEREx is a NASA mission designed to perform an all-sky spectroscopic survey in the 0.75 - 5 m wavelength range. Its primary science objectives are to investigate: (1) inflatio…
K-DRIFT Science Theme: Galaxies in the Faint Universe
Woowon Byun, Yongmin Yoon, Jongwan Ko +17
Low-surface-brightness (LSB) structures serve as evidence of the intricate mass assembly of galaxies, and dedicatedly studying them promises to give us profound insights into the e…
The SPHEREx Satellite Mission
James J. Bock, Asad M. Aboobaker, Joseph Adamo +111
SPHEREx, a NASA explorer satellite launched on 11 March 2025, is carrying out the first all-sky near-infrared spectral survey. The satellite observes in 102 spectral bands from 0.7…
The SPHEREx Target List of Ice Sources (SPLICES)
Matthew L. N. Ashby, Joseph L. Hora, Kiran Lakshmipathaiah +16
One of the primary objectives of the SPHEREx mission is to understand the origin of molecules such as H2O, CO2, and other volatile compounds at the early stages of planetary system…
Search for Extremely Metal-Poor Stars with GEMINI-N/GRACES I. Chemical-Abundance Analysis
Miji Jeong, Young Sun Lee, Timothy C. Beers +5
We present stellar parameters and abundances of 13 elements for 18 very metal-poor (VMP; [Fe/H] -2.0) stars, selected as extremely metal-poor (EMP; [Fe/H] -3.0) candidates…
Optical and near-infrared pulsation properties of RR Lyrae and Population II Cepheid variables in the Messier 15 globular cluster
Anupam Bhardwaj, Marina Rejkuba, G. C. Sloan +2
Messier 15 (NGC 7078) is an old and metal-poor post core-collapse globular cluster which hosts a rich population of variable stars. We report new optical () and near-infrared (…
RR Lyrae variables in Messier 53: Near-infrared Period--Luminosity relations and the calibration using Gaia Early Data Release 3
Anupam Bhardwaj, Marina Rejkuba, Richard de Grijs +6
We present new near-infrared, , Period--Luminosity relations (PLRs) for RR Lyrae variables in the Messier 53 (M53 or NGC 5024) globular cluster. Multi-epoch observat…
Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud V: Multiple Populations in ancient Globular Clusters
Christina K. Gilligan, Brian Chaboyer, Jeffrey D. Cummings +9
We examine four ancient Large Magellanic Cloud (LMC) globular clusters (GCs) for evidence of multiple stellar populations using the Advanced Camera for Surveys and Wide Field Camer…
Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud IV: Evidence for Multiple Populations in Hodge 11 and NGC 2210
Christina K. Gilligan, Brian Chaboyer, Jeffrey D. Cummings +10
We present a multiple population search in two old Large Magellanic Cloud (LMC) Globular Clusters, Hodge 11 and NGC 2210. This work uses data from the Advanced Camera for Surveys a…
RR Lyrae Stars in the Field of Sagittarius II
Seok-Joo Joo, Jaemann Kyeong, Soung-Chul Yang +10
We present the detection of RR Lyrae variable stars in the field of the Sagittarius II (Sgr II) ultra-faint dwarf (UFD) galaxy. Using B, V time-series photometry obtained with the…
RR Lyrae Variable Stars in the Crater II Dwarf Galaxy
Seok-Joo Joo, Jaemann Kyeong, Soung-Chul Yang +10
We report the detection of RR Lyrae variable stars in Crater II, a recently discovered large and diffuse satellite dwarf galaxy of the Milky Way (MW). Based on B, V time-series pho…
Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud: III. Horizontal Branch Morphology
R. Wagner-Kaiser, Dougal Mackey, Ata Sarajedini +5
We leverage new high-quality data from Hubble Space Telescope program GO-14164 to explore the variation in horizontal branch morphology among globular clusters in the Large Magella…
Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud: II. Relative ages and distances for six ancient globular clusters
R. Wagner-Kaiser, Dougal Mackey, Ata Sarajedini +6
We analyze Hubble Space Telescope observations of six globular clusters in the Large Magellanic Cloud from program GO-14164 in Cycle 23. These are the deepest available observation…
The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using only Population II Distance Indicators
Rachael L. Beaton, Wendy L. Freedman, Barry F. Madore +15
We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3 per cent measurement of the Hubble constant using alternative methods to the traditi…
Measurable Relationship Between Bright Galaxies and Their Faint Companions in WHL J085910.0+294957, a Galaxy Cluster at z = 0.30: Vestiges of Infallen Groups?
Joon Hyeop Lee, Hye-Ran Lee, Minjin Kim +8
The properties of satellite galaxies are closely related to their host galaxies in galaxy groups. In cluster environments, on the other hand, the interaction between close neighbor…
The RR Lyrae Variable Population in the Phoenix Dwarf Galaxy
Antonio J. Ordoñez, Soung-Chul Yang, Ata Sarajedini
We present the first detailed study of the RR Lyrae variable population in the Local Group dSph/dIrr transition galaxy, Phoenix, using previously obtained HST/WFPC2 observations of…
The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables
Soung-Chul Yang, Rachel Wagner-Kaiser, Ata Sarajedini +2
We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor gro…
WIYN Open Cluster Study : Wide-Field CCD Photometry of the Old Open Cluster NGC 6819
Soung-Chul Yang, Ata Sarajedini, Constantine P. Deliyannis +3
We present a comprehensive photometric study of the old open cluster, NGC 6819 using 1x1 degree field VI MOSAIC CCD imaging taken with the WIYN 0.9m telescope. The resultant color-…
An Ancient Metal-Poor Population in M32, and Halo Satellite Accretion in M31, Identified by RR Lyrae Stars
Ata Sarajedini, Soung-Chul Yang, Antonela Monachesi +2
We present time-series photometry of two fields near M32 using archival observations from ACS/WFC onboard HST. One field is centered about 2 arcmin from M32 while the other is loca…
HST/WFPC2 Imaging of the Dwarf Satellites And XI and And XIII : HB Morphology and RR Lyraes
Soung-Chul Yang, Ata Sarajedini
We present a study of the stellar populations in two faint M31 dwarf satellites, Andromeda XI and Andromeda XIII. Using archival images from the Wide Field Planetary Camera 2 (WFPC…
RR Lyrae Variables in the Halo of M33
Ata Sarajedini, S. -C. Yang
The properties of RR Lyrae variables make them excellent probes of the formation and evolution of a stellar population. The mere presence of such stars necessitates an age greater…
RR Lyrae Variables in the Local Group Dwarf Galaxy NGC 147
Soung-Chul Yang, Ata Sarajedini
We investigate the RR Lyrae population in NGC 147, a dwarf satellite galaxy of M31 (Andromeda). We used both Thuan-Gunn g-band ground-based photometry from the literature and Hubbl…
Globular Clusters in the Outer Galactic Halo: AM-1 and Palomar 14
Aaron Dotter, Ata Sarajedini, Soung-Chul Yang
AM-1, at ~120 kpc, and Pal 14, at ~70 kpc, are two of the most distant Galactic globular clusters known. We present Hubble Space Telescope WFPC2 photometry of AM-1 and Pal 14 that…