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Related papers: The Star Formation Threshold in NGC 6822

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We present a study on four new star clusters discovered in the halo of the intriguing dwarf irregular galaxy NGC 6822 from a wide field survey covering 3 deg x 3 deg area carried out with MegaCam at Canada-France-Hawaii Telescope (CFHT).…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-15 Narae Hwang , Myung Gyoon Lee , Jong Chul Lee , Won-Kee Park , Hong Soo Park , Sang Chul Kim , Jang-Hyun Park

Using archival near-IR photometry, we identify 51 of the K-band brightest red supergiants (RSGs) in NGC 6822 and compare their physical properties with stellar evolutionary model predictions. We first use Gaia parallax and proper motion…

Solar and Stellar Astrophysics · Physics 2022-01-26 Tzvetelina A. Dimitrova , Kathryn F. Neugent , Philip Massey , Emily M. Levesque

We present the results of a galaxy-wide study of molecular gas and star formation in a sample of 76 HII regions in the nearby spiral galaxy NGC 300. We have measured the molecular gas at 250 pc scales using pointed CO(J=2-1) observations…

Astrophysics of Galaxies · Physics 2015-06-19 Christopher M. Faesi , Charles J. Lada , Jan Forbrich , Karl Menten , Herve Bouy

In turbulent fragmentation, star formation occurs in condensations created by converging flows. The condensations must be sufficiently massive, dense and cool to be gravitationally unstable, so that they start to contract; {\it and} they…

Astrophysics of Galaxies · Physics 2016-05-20 A. P. Whitworth

We present a supervised machine learning methodology to classify stellar populations in the Local Group dwarf-irregular galaxy NGC6822. Near-IR colours (J-H, H-K, and J-K), K-band magnitudes and far-IR surface brightness (at 70 and 160…

Astrophysics of Galaxies · Physics 2021-08-25 David A. Kinson , Joana M. Oliveira , Jacco Th. van Loon

We investigate the relation between star formation rates and local galaxy environment for a stellar mass selected galaxy sample in the redshift range 1.5 < z < 3. We use near-infra-red imaging from an extremely deep Hubble Space Telescope…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 R. Gruetzbauch , C. J. Conselice , A. E. Bauer , A. F. L. Bluck , R. W. Chuter , F. Buitrago , A. Mortlock , T. Weinzirl , S. Jogee

The timescale for star formation, a measure of how quickly neutral gas is being converted to stars, is considerably longer than typical dynamical timescales associated with a galactic disk. For purposes of modeling galaxy evolution,…

Astrophysics of Galaxies · Physics 2014-11-20 Tony Wong

There is a well known disparity between the evolution the star formation rate density, {\psi}*, and the abundance of neutral hydrogen (HI), the raw material for star formation. Recently, however, we have shown that {\psi}* may be correlated…

Astrophysics of Galaxies · Physics 2019-02-04 S. J. Curran

We have analysed archival ROSAT PSPC and Einstein HRI data for the x-ray point source in the bar of NGC 6822. The source decreased in x-ray flux by at least half an order of magnitude in the 13 years between the HRI and PSPC observations.…

Astrophysics · Physics 2012-08-27 Paul B. Eskridge , Raymond E. White , III

High spatial and spectral resolution observations of the atomic interstellar medium in nearby dwarf galaxies reveal evidence for warm and cold neutral gas, just like the phases in our own Galaxy. The cold or quiescent phase (about 20% of…

Astrophysics · Physics 2009-04-13 L. M. Young , L. van Zee , R. C. Dohm-Palmer , K. Y. Lo

We present a study of a star formation prescription in which star formation efficiency depends on local gas density and turbulent velocity dispersion, as suggested by direct simulations of SF in turbulent giant molecular clouds (GMCs). We…

Astrophysics of Galaxies · Physics 2017-08-22 Vadim A. Semenov , Andrey V. Kravtsov , Nickolay Y. Gnedin

In the local Universe, galaxy properties show a strong dependence on environment. In cluster cores, early type galaxies dominate, whereas star-forming galaxies are more and more common in the outskirts. At higher redshifts and in somewhat…

The [CII] 157.74 $\mu$m transition is the dominant coolant of the neutral interstellar gas, and has great potential as a star formation rate (SFR) tracer. Using the Herschel KINGFISH sample of 46 nearby galaxies, we investigate the relation…

Super star clusters are young, compact star clusters found in the central regions of interacting galaxies. Recently, they have also been reported to preferentially form in certain tidal tails, but not in others. In this paper, we have used…

Astrophysics · Physics 2009-11-13 A. Maybhate , J. Masiero , J. E. Hibbard , J. C. Charlton , C. Palma , K. A. Knierman , J. English

Stellar distance is an important basic parameter in stellar astrophysics. Stars in a cluster are thought to be formed coevally from the same interstellar cloud of gas and dust. They are therefore expected to have common properties. These…

Solar and Stellar Astrophysics · Physics 2015-06-19 Tao Wu , Yan Li , Saskia Hekker

We study the connection of star formation to atomic (HI) and molecular hydrogen (H$_2$) in isolated, low metallicity dwarf galaxies with high-resolution ($m_{\rm gas}$ = 4 M$_\odot$, $N_{\rm ngb}$ = 100) SPH simulations. The model includes…

Astrophysics of Galaxies · Physics 2016-03-23 Chia-Yu Hu , Thorsten Naab , Stefanie Walch , Simon C. O. Glover , Paul C. Clark

We present the star formation history (SFH) of the isolated (D~970 kpc) Local Group dwarf galaxy WLM measured from color-magnitude diagrams constructed from deep Hubble Space Telescope imaging. Our observations include a central (0.5 $r_h$)…

We present spectroscopy of two clusters in the dwarf irregular galaxy NGC 6822. From these we deduce an age for Cluster VII of 11 Gyr and [Fe/H] = -1.95 +/- 0.15 dex. Cluster VII appears to be an analog of the metal-poor galactic globular…

Astrophysics · Physics 2009-10-30 Judith G. Cohen , John P. Blakeslee

Within the key project "Herschel M33 extended survey" (HerM33es), we are studying the physical and chemical processes driving star formation and galactic evolution in the nearby galaxy M33, combining the study of local conditions affecting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 C. Kramer , M. Boquien , J. Braine , C. Buchbender , D. Calzetti , P. Gratier , B. Mookerjea , M. Relano , S. Verley

Using combinations of H\alpha, ultraviolet (UV), and infrared (IR) emission, we estimate the star formation rate (SFR) surface density, \Sigma_SFR, at 1 kpc resolution for 30 disk galaxies that are targets of the IRAM HERACLES CO survey. We…

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