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Related papers: Magellan/M2FS Spectroscopy of the Reticulum 2 Dwar…

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We present spectroscopic data for 16369 stellar targets within and/or toward 38 dwarf spheroidal galaxies and faint star clusters within the Milky Way halo environment. All spectra come from observations with the multi-object, fiber-fed…

The ultra-faint dwarf galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey. We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber…

We present results from spectroscopic observations with the Michigan/Magellan Fiber System (M2FS) of $147$ stellar targets along the line of sight to the newly-discovered `ultrafaint' stellar systems Tucana 2 (Tuc 2) and Grus 1 (Gru 1).…

Photometry alone is not sufficient to unambiguously distinguish between ultra-faint star clusters and dwarf galaxies because of their overlap in morphological properties. Here we report on VLT/GIRAFFE spectra of candidate member stars in…

We introduce a stellar velocity survey of dwarf spheroidal galaxies, undertaken using the Michigan/MIKE Fiber System (MMFS) at the Magellan/Clay 6.5 m telescope at Las Campanas Observatory. As of 2006 November we have used MMFS to collect…

Reticulum II (Ret II) is a satellite galaxy of the Milky Way and presents a prime target to investigate the nature of dark matter (DM) because of its high mass-to-light ratio. We evaluate a dedicated INTEGRAL observation campaign data set…

High Energy Astrophysical Phenomena · Physics 2022-01-26 Thomas Siegert , Celine Boehm , Francesca Calore , Roland Diehl , Martin G. H. Krause , Pasquale D. Serpico , Aaron C. Vincent

We present Magellan/IMACS and Magellan/MIKE spectroscopy of the ultra-faint dwarf (UFD) galaxy Pictor~II (Pic~II) that is located only 12 kpc from the Large Magellanic Cloud (LMC). From the IMACS spectroscopy, we identify 13 member stars…

We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II. These stars span the full metallicity range of Ret II (-3.5 <…

Astrophysics of Galaxies · Physics 2016-10-26 Alexander P. Ji , Anna Frebel , Joshua D. Simon , Anirudh Chiti

The ultra-faint dwarf galaxy Reticulum~II was enriched by a single rare and prolific r-process event. The r-process content of Reticulum~II thus provides a unique opportunity to study metal mixing in a relic first galaxy. Using multi-object…

We apply a Bayesian method to model multi-epoch radial velocity measurements in the ultra-faint dwarf galaxy Reticulum II, fully accounting for the effects of binary orbital motion and systematic offsets between different spectroscopic…

Astrophysics of Galaxies · Physics 2019-06-12 Quinn E. Minor , Andrew B. Pace , Jennifer L. Marshall , Louis E. Strigari

The dwarf spheroidal galaxies (dSph) of the Milky Way are among the most attractive targets for indirect searches of dark matter. In this work, we reconstruct the dark matter annihilation (J-factor) and decay profiles for the newly…

High Energy Astrophysical Phenomena · Physics 2015-07-29 V. Bonnivard , C. Combet , D. Maurin , A. Geringer-Sameth , S. M. Koushiappas , M. G. Walker , M. Mateo , E. Olszewski , J. I. Bailey

We present results from MMT/Hectochelle spectroscopy of red giant candidate stars along the line of sight to the recently-discovered Galactic satellite Crater 2. Modelling the joint distribution of stellar positions, velocities and…

Binary stars can inflate the observed velocity dispersion of stars in dark matter dominated systems such as ultra-faint dwarf galaxies (UFDs). However, the population of binaries in UFDs is poorly constrained by observations, with preferred…

Astrophysics of Galaxies · Physics 2022-05-18 Mohammadtaher Safarzadeh , Joshua D. Simon , Abraham Loeb

The recent discovery of ten new dwarf galaxy candidates by the Dark Energy Survey (DES) and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) could increase the Fermi Gamma-Ray Space Telescope's sensitivity to…

High Energy Astrophysical Phenomena · Physics 2015-09-16 Dan Hooper , Tim Linden

We present new MMT/Hectochelle spectroscopic measurements for 257 stars observed along the line of sight to the ultra-faint dwarf galaxy Triangulum II. Combining with results from previous Keck/DEIMOS spectroscopy, we obtain a sample that…

We present an extensive spectroscopic follow-up campaign of 29 strong lensing (SL) selected galaxy clusters discovered primarily in the Second Red-Sequence Cluster Survey (RCS-2). Our spectroscopic analysis yields redshifts for 52…

Star formation in ultra-faint dwarf galaxies (UFDs, $M_* <10^5M_\odot$) is suppressed by reionization, but may not be completely quenched. The metallicity distribution function (MDF) of stars in ultra-faint dwarf galaxies could show these…

We report new spectroscopic observations obtained with the Michigan/Magellan Fiber System of 308 red giants (RGs) located in two fields near the photometric center of the bar of the Large Magellanic Cloud. This sample consists of 131 stars…

Astrophysics of Galaxies · Physics 2017-05-31 Ying-Yi Song , Mario Mateo , Matthew G. Walker , Ian U. Roederer

We investigate the possibility that the dwarf galaxies Crater II and Hercules have previously been tidally stripped by the Milky Way. We present Magellan/IMACS spectra of candidate member stars in both objects. We identify 37 members of…

Astrophysics of Galaxies · Physics 2019-09-25 Sal Wanying Fu , Joshua D. Simon , Alex G. Alarcón Jara
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