Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We derive the circular velocity curves of the gaseous and stellar discs of UGC 4056, a giant barred galaxy with an active galactic nucleus (AGN). We analyse UGC 4056 using the 2D spectroscopy obtained within the framework of the Mapping Nearby Galaxies at APO (MaNGA) survey. Using images and the colour index g − r from the Sloan Digital Sky Survey (SDSS), we determined the tilt of the galaxy, which allows us to conclude that the galaxy rotates clockwise with trailing spiral arms. We found that the gas motion at the central part of the UGC 4056 shows peculiar features. The rotation velocity of the gaseous disc shows a bump within around three kiloparsecs while the rotation velocity of the stellar disc falls smoothly to zero with decreasing galactocentric distance. We demonstrate that the peculiar radial velocities in the central part of the galaxy may be caused by the inflow of the gas towards the nucleus of the galaxy. The unusual motion of the gas takes place at the region with the AGN-like radiation and can be explained by the gas response to the bar potential.

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The Apache Point Observatory Galactic Evolution Experiment (APOGEE)

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310003558 ◽

2009 ◽

Vol 5 (S262) ◽

pp. 428-429

Author(s):

Ricardo P. Schiavon ◽

Steven R. Majewski

Keyword(s):

Large Scale ◽

Near Infrared ◽

Milky Way ◽

Galactic Evolution ◽

Sloan Digital Sky Survey ◽

Elemental Abundances ◽

Sky Survey ◽

The Galaxy ◽

Evolution Experiment ◽

Under Construction

AbstractThe Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a large scale, high-resolution, near-infrared spectroscopic survey of Milky Way stellar populations and one of the four experiments in the Sloan Digital Sky Survey III (SDSS-III). APOGEE will be based on a new multi-fiber cryogenic spectrograph, currently under construction, expected to begin survey observations on the 2.5 m Sloan telescope in the Spring of 2011. APOGEE will measure high-precision radial velocities and elemental abundances for ~15 elements for ~ 105 stars, and is expected to shed new light on the processes that led to the formation of the Galaxy.

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On the stark difference in satellite distributions around the Milky Way and Andromeda

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stt2058 ◽

2014 ◽

Vol 439 (1) ◽

pp. 73-82 ◽

Cited By ~ 25

Author(s):

Basilio Yniguez ◽

Shea Garrison-Kimmel ◽

Michael Boylan-Kolchin ◽

James S. Bullock

Keyword(s):

Radial Distribution ◽

Cold Dark Matter ◽

Milky Way ◽

Dwarf Galaxies ◽

Sloan Digital Sky Survey ◽

The Sun ◽

Angular Anisotropy ◽

Satellite Systems ◽

Sky Survey ◽

Number Counts

Abstract We compare spherically averaged radial number counts of bright (≳105 L⊙) dwarf satellite galaxies within 400 kpc of the Milky Way (MW) and M31 and find that the MW satellites are much more centrally concentrated. Remarkably, the two satellite systems are almost identical within the central 100 kpc, while M31 satellites outnumber MW satellites by about a factor of 4 at deprojected distances spanning 100–400 kpc. We compare the observed distributions to those predicted for Λ cold dark matter (ΛCDM) subhaloes using a suite of 44 high-resolution ∼1012 M⊙ halo zoom simulations, 22 of which are in pairs like the MW and M31. We find that the radial distribution of satellites around M31 is fairly typical of those predicted for subhaloes, while the MW's distribution is more centrally concentrated than any of our simulated ΛCDM haloes. One possible explanation is that our census of bright (≳105 L⊙) MW dwarf galaxies is significantly incomplete beyond ∼100 kpc of the Sun. If there were ∼8–20 more bright dwarfs orbiting undetected at 100–400 kpc distance, then the MW's radial distribution would fall within the range expected from subhalo distributions and also look very much like the known M31 system. We use our simulations to demonstrate that there is enough area left unexplored by the Sloan Digital Sky Survey and its extensions that the discovery of ∼10 new bright dwarfs is not implausible given the expected range of angular anisotropy of subhaloes in the sky.

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