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Related papers: Kinematics and Composition of the Galactic Bulge: …

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We report the detection of the Galactic nuclear disc in line-of-sight kinematics of stars, measured with infrared spectroscopy from APOGEE. This stellar component of the nuclear disc has an extent and rotation velocity V ~ 120kms comparable…

Astrophysics of Galaxies · Physics 2015-10-21 Ralph Schönrich , Michael Aumer , Stuart E. Sale

We provide new insight on the origin of the cold high-V$_{\rm los}$ peaks ($\sim$200 kms$^{-1}$) in the Milky Way bulge discovered in the APOGEE commissioning data \citep{Nidever2012}. Here we show that such kinematic behaviour present in…

Astrophysics of Galaxies · Physics 2017-08-22 J. G. Fernández-Trincado , A. C. Robin , E. Moreno , A. Pérez-Villegas , B. Pichardo

We describe a novel framework to model galaxy spectra with two cospatial stellar populations, such as may represent a bulge & bar or thick & thin disc, and apply it to APOGEE spectra in the inner $\sim$2 kpc of M31, as well as to stacked…

We revisit the stellar velocity distribution in the Galactic bulge/bar region with APOGEE DR16 and {\it Gaia} DR2, focusing in particular on the possible high-velocity (HV) peaks and their physical origin. We fit the velocity distributions…

Astrophysics of Galaxies · Physics 2021-02-17 Yingying Zhou , Zhao-Yu Li , Iulia Simion , Juntai Shen , Shude Mao , Chao Liu , Mingjie Jian , José. G. Fernández-Trincado

Results of recent observations of the Galactic bulge demand that we discard a simple picture of its formation, suggesting the presence of two stellar populations represented by two peaks of stellar metallicity distribution (MDF) in the…

Astrophysics of Galaxies · Physics 2015-06-03 Takuji Tsujimoto , Kenji Bekki

$Aims$. The existence of massive disc galaxies with little or no bulge challenges conventional $\Lambda$ cold dark matter model, which typically favours dynamically hot central structures due to early collapse and mergers. The study of…

Recent progress on the structure and dynamics of bulges is reviewed. Those aspects that link galaxy bulges either to oblate spheroids akin to elliptical galaxies or to rapidly-rotating, flattened systems more nearly resembling the products…

Astrophysics · Physics 2007-05-23 Marc Balcells

The origin of the high-alpha component of the Galactic bulge remains debated, unlike the bar-driven origin of the low-alpha bulge. We examine the metallicity-dependent dynamical properties of high-[Mg/Fe] stars in the bar region, using…

Astrophysics of Galaxies · Physics 2025-09-19 Aakash Pandey , Ortwin Gerhard

This is the first of a series of papers devoted to the investigation of a large sample of brightest cluster galaxies (BCGs), their kinematic and stellar population properties, and the relationships between those and the properties of the…

Astrophysics · Physics 2009-11-13 S. I. Loubser , A. E. Sansom , P. Sanchez-Blazquez , I. K. Soechting , G. E. Bromage

As galactic halos are not directly visible, there are many ambiguities regarding their composition and rotational velocity. Though most of the dark matter is non-baryonic, {\it some fraction is}, and it can be used to trace the halo…

Astrophysics of Galaxies · Physics 2023-01-10 Noraiz Tahir , Francesco De Paolis , Asghar Qadir , Achille A. Nucita

We have derived absolute proper motions of the entire Galactic bulge region from VIRAC and Gaia. We present these as both integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of distance using RC…

Astrophysics of Galaxies · Physics 2019-12-06 Jonathan P. Clarke , Christopher Wegg , Ortwin Gerhard , Leigh C. Smith , Phil W. Lucas , Shola M. Wylie

CONTEXT: [ABRIDGED]. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compare Galactic chemical evolution models to observational data for this still…

Astrophysics of Galaxies · Physics 2021-12-01 T. Bensby , A. Gould , M. Asplund , S. Feltzing , J. Meléndez , J. A. Johnson , S. Lucatello , A. Udalski , J. C. Yee

The Galactic bulge, that is the prominent out-of-plane over-density present in the inner few kiloparsecs of the Galaxy, is a complex structure, as the morphology, kinematics, chemistry and ages of its stars indicate. To understand the…

Astrophysics of Galaxies · Physics 2016-07-06 P. Di Matteo

We report on the RR Lyrae variable star, MACHO 176.18833.411, located toward the Galactic bulge and observed within the data from the ongoing Bulge RR Lyrae Radial Velocity Assay (BRAVA-RR), which has the unusual radial velocity of -372 +-…

We dissect giant Sc-Scd galaxies with Hubble Space Telescope photometry and Hobby-Eberly Telescope spectroscopy. We use HET's High Resolution Spectrograph (resolution = 15,000) to measure stellar velocity dispersions in the nuclear star…

Astrophysics of Galaxies · Physics 2015-05-20 John Kormendy , Niv Drory , Ralf Bender , Mark E. Cornell

We discuss the jet kinematics of a complete flux-density-limited sample of 135 radio-loud active galactic nuclei (AGN) resulting from a 13 year program to investigate the structure and evolution of parsec-scale jet phenomena. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 M. L. Lister , M. H. Cohen , D. C. Homan , M. Kadler , K. I. Kellermann , Y. Y. Kovalev , E. Ros , T. Savolainen , J. A. Zensus

We report results from an exploratory study implementing a new probe of Galactic evolution using archival Hubble Space Telescope imaging observations. Precise proper motions are combined with photometric relative metallicity and temperature…

Based on the LAMOST survey and Sloan Digital Sky Survey (SDSS), we use low-resolution spectra of 130,043 F/G-type dwarf stars to study the kinematics and metallicity properties of the Galactic disk. Our study shows that the stars with…

Astrophysics of Galaxies · Physics 2016-10-12 Yingjie Jing , Cuihua Du , Jiayin Gu , Yunpeng Jia , Xiyan Peng , Yuqin Chen , Zhenyu Wu , Jun Ma , Xu Zhou , Zihuang Cao , Yonghui Hou , Yuefei Wang , Yong Zhang

We present a detailed study of the shape of the innermost part of the rotation curves of a sample of 29 nearby spiral galaxies, based on high angular and spectral resolution kinematic Halpha Fabry-Perot observations. In particular, we…

The rotation of the galactic halos is a fascinating topic which is still waiting to be addressed. Planck data has shown the existence of a temperature asymmetry towards the halo of several nearby galaxies, such as M31, NGC 5128, M33, M81,…

Astrophysics of Galaxies · Physics 2021-11-17 Noraiz Tahir , Francesco De Paolis , Asghar Qadir , Achille A. Nucita