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Related papers: Stellar Streams and Clouds in the Galactic Halo

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The detection of narrow channels of accretion toward protostellar disks, known as streamers, have increased in number in the last few years. However, it is unclear if streamers are a common feature around protostars that were previously…

We present surface photometry of a very faint, giant arc feature in the halo of the nearby spiral galaxy NGC 5055 (M63) that is consistent with being a part of a stellar stream resulting from the disruption of a dwarf satellite galaxy. This…

There are expected to be physical relationships between the globular clusters (GCs) and stellar substructures in the Milky Way, not all of which have yet been found. We search for such substructures from a combined halo sample of SDSS blue…

Astrophysics of Galaxies · Physics 2020-08-05 Zhen Yuan , Jiang Chang , Timothy C. Beers , Yang Huang

Standard cosmology predicts that dwarfs were the first galaxies to be formed in the Universe and that many of them merge afterwards to form bigger galaxies such as the Milky Way. This process would have left behind traces such as tidal…

Astrophysics · Physics 2007-05-23 D. Martinez-Delgado , M. A. Gomez-Flechoso , A. Aparicio

Based on the second Gaia data release (Gaia DR2) and spectroscopy from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data, we identified 20,089 halo stars kinematically and chemically. The halo streams in the solar…

Astrophysics of Galaxies · Physics 2019-04-03 Hefan Li , Cuihua Du , Shuai Liu , Thomas Donlon , Heidi Jo Newberg

Using high-resolution spectra of nearby F and G dwarf stars, we have investigated the detailed abundance and age structure of the Hercules stream. We find that the stars in the stream have a wide range of stellar ages, metallicities, and…

Astrophysics · Physics 2009-11-11 T. Bensby , M. S. Oey , S. Feltzing , B. Gustafsson

We present an analysis of Galactic halo structure and substructure traced by ~500 RR Lyrae stars in the SDSS stripe 82 region. The main result of this study is a 2D map of the Galactic halo that reaches distances of 100 kpc and traces…

Astrophysics of Galaxies · Physics 2011-05-23 Branimir Sesar

Thin stellar streams originating from globular clusters are among the most sensitive tracers of low-mass dark-matter subhalos. Joint analysis of the entire population of stellar streams will place the most robust constraints on the…

Astrophysics of Galaxies · Physics 2024-10-08 Sarah Pearson , Ana Bonaca , Yingtian Chen , Oleg Y. Gnedin

We report on the discovery in the Gaia DR3 astrometric and spectroscopic catalog of a new polar stream that is found as an over-density in action space. This structure is unique as it has an extremely large apocenter distance, reaching…

The Magellanic Stream (MS) has long been known to contain multiple H I strands and corresponding stellar populations are beginning to be discovered. Combining a sample of 17 stars from the H3 ("Hectochelle in the Halo at High Resolution")…

Astrophysics of Galaxies · Physics 2025-02-19 Dennis Zaritsky , Vedant Chandra , Charlie Conroy , Ana Bonaca , Phillip A. Cargile , Rohan P. Naidu

Our Galaxy is thought to have undergone an active evolutionary history dominated by star formation, the accretion of cold gas, and, in particular, mergers up to 10 gigayear ago. The stellar halo reveals rich fossil evidence of these…

The past two decades have seen extensive surveys of the far-infrared to submillimeter continuum emission in the plane of our Galaxy. We line out prospects for the coming decade for corresponding molecular and atomic line surveys which are…

It has been suggested that star-forming galaxies may host a substantial, dark reservoir of gas in the form of planetary-mass molecular clouds that are so cold that $\text{H}_{2}$ can condense. Here we investigate the process of tidal…

Astrophysics of Galaxies · Physics 2025-04-01 Arthur G. Suvorov , Mark A. Walker

A new overdensity of A-colored stars in distant parts of the Milky Way's stellar halo, at a dereddened SDSS magnitude of g_0 = 20.3, is presented. Identification of associated variable RR Lyrae candidates supports the claim that these are…

It has been proposed that the Hercules stream, a group of co-moving stars in the Solar neighborhood offset from the bulk of the velocity distribution, is the result of resonant interactions between stars in the outer disk and the Galactic…

Astrophysics of Galaxies · Physics 2010-12-01 Jo Bovy

In the hierarchical formation scenario in which the outer halo of the Milky Way is the result of the continuous accretion of low-mass galaxies, a fraction of the Galactic globular cluster system might have originated in and been accreted…

In this paper we report a study (see Mastrobuono-Battisti et al., 2012) about the formation and characteristics of the tidal tails around Palomar 5 along its orbit in the Milky Way potential, by means of direct N-body simulations and…

Astrophysics of Galaxies · Physics 2013-04-25 Alessandra Mastrobuono-Battisti , Paola Di Matteo , Marco Montuori , Misha Haywood

The Magellanic Stream is a 100\deg x 10\deg filament of gas which lies within the Galactic halo and contains ~ 2 x 10^8 \Msun of neutral hydrogen. We present data from the HI Parkes All Sky Survey (HIPASS) in the first complete survey of…

Astrophysics · Physics 2008-11-26 M. E. Putman , L. Staveley-Smith , K. C. Freeman , B. K. Gibson , D. G. Barnes

Nearly a hundred progenitor-less, thin stellar streams have been discovered in the Milky Way, thanks to Gaia and related surveys. Most streams are believed to have formed from star clusters and it was recently proposed that extended star…

Astrophysics of Galaxies · Physics 2025-02-24 Daniel Roberts , Mark Gieles , Denis Erkal , Jason L. Sanders

The longest recognized stellar stream in the Milky Way Galaxy has an expanse of over more than half the north sky. There was a physical disturbance within the stream, 500 million years ago, which could have been the scar of a dark matter…

Astrophysics of Galaxies · Physics 2022-11-29 Carissma McGee