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Related papers: The Star Formation Threshold in NGC 6822

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From a 2 x 2 degree survey of NGC 6822 we have previously established that this Local Group dwarf irregular galaxy possesses a huge spheroid having more than one degree in length. This spheroid is in rotation but its rotation curve is known…

Astrophysics · Physics 2009-11-11 S. Demers , P. Battinelli , E. Artigau

We analyze images of BIMA 12CO (J = 1 --> 0), VLA HI, and Spitzer 3.6 and 24 \mum emission toward the edge-on galaxy NGC 891 and derive the radial and vertical distributions of gas and the radial distributions of stellar mass and recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Kijeong Yim , Tony Wong , J. Christopher Howk , J. M. van der Hulst

NGC 6822 is the closest isolated dwarf irregular galaxy to the Milky Way. Its proximity and stellar mass ($10^8 M_\odot$, large for a dwarf galaxy) allow for a detailed study of its kinematic properties. The red giant branch (RGB) stars at…

Astrophysics of Galaxies · Physics 2020-11-04 Brent Belland , Evan Kirby , Michael Boylan-Kolchin , Coral Wheeler

We present the ALMA survey of CO(2-1) emission from the 1/5 solar metallicity, Local Group dwarf galaxy NGC 6822. We achieve high (0.9 arcsec ~ 2 pc) spatial resolution while covering large area: four 250 pc x 250 pc regions that encompass…

The metallicity gradient and the stellar distribution within the Local Group dwarf galaxy NGC 6822 has been studied photometrically using asymptotic branch stars (AGB). In order to study the stellar and metallicity distribution, the carbon-…

Solar and Stellar Astrophysics · Physics 2010-11-22 L. F. Sibbons , M. -R. L. Cioni , M. Irwin , M. Rejkuba

The star complexes (large scale star forming regions) of NGC 6822 were traced and mapped and their size distribution was compared with the size distribution of star complexes in the Magellanic Clouds (MCs). Furthermore, the spatial…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 A. Karampelas , A. Dapergolas , E. Kontizas , E. Livanou , M. Kontizas , I. Bellas-Velidis , J. M. Vilchez

Star formation depends on the available gaseous "fuel" as well as galactic environment, with higher specific star formation rates where gas is predominantly molecular and where stellar (and dark matter) densities are higher. The partition…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Eve C. Ostriker

The inner few hundred parsecs of the Milky Way harbours gas densities, pressures, velocity dispersions, an interstellar radiation field and a cosmic ray ionisation rate orders of magnitude higher than the disc; akin to the environment found…

Astrophysics of Galaxies · Physics 2017-06-21 A. T. Barnes , S. N. Longmore , C. Battersby , J. Bally , J. M. D. Kruijssen , J. D. Henshaw , D. L. Walker

We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at 8500 Angstroms was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line of sight…

Astrophysics of Galaxies · Physics 2016-02-08 Jesse Swan , Andrew A. Cole , Eline Tolstoy , Mike J. Irwin

We present new ~1" resolution data of the dense molecular gas in the central 50-100 pc of four nearby Seyfert galaxies. PdBI observations of HCN and, in 2 of the 4 sources, simultaneously HCO+ allow us to carefully constrain the dynamical…

We use new ALMA observations to investigate the connection between dense gas fraction, star formation rate, and local environment across the inner region of four local galaxies showing a wide range of molecular gas depletion times. We map…

We measure the star formation efficiency (SFE), the star formation rate per unit gas, in 23 nearby galaxies and compare it to expectations from proposed star formation laws and thresholds. We use HI maps from THINGS and derive H2 maps from…

In the Local Group spiral galaxy M33, we investigate the correlation between the star formation rate (SFR) surface density, Sigma_SFR, and the gas density Sigma_gas (molecular, atomic, and total). We also explore whether there are other…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 S. Verley , E. Corbelli , C. Giovanardi , L. K. Hunt

We present new, high sensitivity VLA observations of HI in four dwarf galaxies (UGCA 292, GR8, DDO 210, and DDO 216) and we use these data to study interactions between star formation and the interstellar medium. HI velocity dispersions and…

Astrophysics · Physics 2016-08-30 L. M. Young , L. van Zee , K. Y. Lo , R. C. Dohm-Palmer , M. E. Beierle

We present the results of large-area CO J=3-2 emission mapping of three nearby field galaxies, NGC 628, NGC 3521, and NGC 3627, completed at the James Clerk Maxwell Telescope as part of the Nearby Galaxies Legacy Survey. These galaxies all…

We use observed radial profiles of mass surface densities of total, $\Sigma_g$, & molecular, $\Sigma_{\rm H2}$, gas, rotation velocity & star formation rate (SFR) surface density, $\Sigma_{\rm sfr}$, of the molecular-rich ($\Sigma_{\rm…

Astrophysics of Galaxies · Physics 2015-06-19 Chutipong Suwannajak , Jonathan C. Tan , Adam K. Leroy

[abridged] While observations of Local Group galaxies show a very simple, local star formation law in which the star formation rate per unit area in each patch of a galaxy scales linearly with the molecular gas surface density, recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mark R. Krumholz , Avishai Dekel , Christopher F. McKee

We investigate the relationship between HI, H_2, and the star formation rate (SFR) using azimuthally averaged data for seven CO-bright spiral galaxies. Contrary to some earlier studies based on global fluxes, we find that the SFR surface…

Astrophysics · Physics 2009-11-07 Tony Wong , Leo Blitz

We report on the internal distribution of star formation efficiency in IRAS 08339+6517 (hereafter IRAS08), using $\sim$200~pc resolution CO(2-1) observations from NOEMA. The molecular gas depletion time changes by 2 orders-of-magnitude from…

Astrophysics of Galaxies · Physics 2022-04-13 D. B. Fisher , A. D. Bolatto , K. Glazebrook , D. Obreschkow , R. G. Obreschkow , G. G. Kacprzak , N. M. Nielsen

We summarize some of the results obtained from Herschel surveys of the nearby star forming regions and the Galactic plane. We show that in the nearby star forming regions the starless core spatial surface density distribution is very…

Astrophysics of Galaxies · Physics 2015-06-12 Leonardo Testi , Eli Bressert , S. Longmore