English
Related papers

Related papers: Touching The Void: A Striking Drop in Stellar Halo…

200 papers

We develop statistical methods for identifying star streams in the halo of the Milky Way galaxy that exploit observed spatial and radial velocity distributions. Within a great circle, departures of the observed spatial distribution from…

Astrophysics of Galaxies · Physics 2015-06-03 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of…

Astrophysics of Galaxies · Physics 2017-09-20 Ericson López , Jairo Armijos , Mario Llerena , Franklin Aldás

There is mounting evidence for an extra-planar gas layer around the Milky Way disk, similar to the anomalous HI gas detected in a few other galaxies. As much as 10% of the gas may be in this phase. We analyze HI clouds located in the…

Astrophysics of Galaxies · Physics 2015-05-14 L. Dedes , P. W. M Kalberla

We combine the Siding Spring Survey of RR Lyrae stars with the Southern Proper Motion Catalog 4, in order to detect and kinematically characterize overdensities in the inner halo of the Milky Way. We identify one such overdensity above the…

Astrophysics of Galaxies · Physics 2015-09-09 D. I. Casetti-Dinescu , D. A. Nusdeo , T. M. Girard , V. I. Korchagin , W. F. van Altena

We describe a correlation function statistic that quantifies the amount of spatial and kinematic substructure in the stellar halo. We test this statistic using model stellar halo realizations constructed from the Aquarius suite of six…

Astrophysics of Galaxies · Physics 2015-05-20 A. P. Cooper , S. Cole , C. S. Frenk , A. Helmi

In an effort to more precisely define the spatial distribution of Galactic field stars, we present an analysis of the photometric parallaxes of 70,000 stars covering nearly 15 square degrees in seven Kapteyn Selected Areas. We address the…

Astrophysics · Physics 2009-11-07 M. H. Siegel , S. R. Majewski , I. N. Reid , I. B. Thompson

We use deep surface photometry of the giant elliptical M49 (NGC 4472), obtained as part of our survey for diffuse light in the Virgo Cluster, to study the stellar populations in its outer halo. Our data trace M49's stellar halo out to ~ 100…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Chris Mihos , Paul Harding , Craig Rudick , John Feldmeier

The existence of stellar halos around galaxies is a natural prediction of the hierarchical nature of the LambdaCDM model. Recent observations of Milky Way-like galaxies have revealed a wide range in stellar halo mass, including cases with…

A simple model for the Milky Way halo is presented. It has a flat rotation curve in the inner regions, but the density falls off sharply beyond an outer edge. This truncated, flat rotation curve (TF) model possesses a rich family of simple…

Astrophysics · Physics 2008-11-26 M. I. Wilkinson , N. W. Evans

The distribution of Milky Way halo blue horizontal-branch (BHB) stars is examined using action-based extended distribution functions (EDFs) that describe the locations of stars in phase space, metallicity, and age. The parameters of the…

Astrophysics of Galaxies · Physics 2016-08-29 Payel Das , Angus Williams , James Binney

We constrain the shape of the Milky Way's halo by dynamical modeling of the observed phase-space tracks of the Pal 5 and GD-1 tidal streams. We find that the only information about the potential gleaned from the tracks of these streams are…

Astrophysics of Galaxies · Physics 2017-02-10 Jo Bovy , Anita Bahmanyar , Tobias K. Fritz , Nitya Kallivayalil

The formation of the Milky Way stellar halo is thought to be the result of merging and accretion of building blocks such as dwarf galaxies and massive globular clusters. Recently, Deason et al. (2015) suggested that the Milky Way outer halo…

Astrophysics of Galaxies · Physics 2015-12-02 Chul Chung , Young-Wook Lee , Mario Pasquato

We present a panoramic map of the entire Milky Way halo north of dec~-30 degrees (~30,000 deg^2), constructed by applying the matched-filter technique to the Pan-STARRS1 3Pi Survey dataset. Using single-epoch photometry reaching to g~22, we…

Our current understanding of how dark matter (DM) is distributed within the Milky Way halo, particularly in the solar neighborhood, is based on either careful studies of the local stellar orbits, model assumptions on the global shape of the…

We present 3D kinematic observations of stars within the central 0.5 pc of the Milky Way nuclear star cluster using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a…

Astrophysics of Galaxies · Physics 2015-06-17 T. Do , G. D. Martinez , S. Yelda , A. M. Ghez , J. Bullock , M. Kaplinghat , J. R. Lu , A. G. H. Peter , K. Phifer

We analyse a 10,000 star spectroscopic survey, focused on Galactic thick disk stars typically 2-5 kpc from the Sun, carried out using the AAOmega Spectrograph on the AAT. We develop methods for completeness-correction of the survey based on…

Astrophysics of Galaxies · Physics 2015-06-15 Apoorva Jayaraman , Gerard Gilmore , Rosemary F. G. Wyse , John E. Norris , Vasily Belokurov

Taking advantage of the ultra-deep near-infrared imaging obtained with the Hubble Space Telescope on the Hubble Ultra Deep Field, we detect and explore for the first time the properties of the stellar haloes of two Milky Way-like galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ignacio Trujillo , Judit Bakos

We report on the discovery of a new Milky Way companion stellar system located at (RA, Dec) = (22h10m43.15s, +14:56:58.8). The discovery was made using the eighth data release of SDSS after applying an automated method to search for…

We present results on gas flows in the halo of a Milky Way-like galaxy at z=0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution towards an extended…