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Related papers: A continuous low star formation rate in IZw 18 ?

200 papers

A possible formation mechanism of hydrogen molecules on a galactic scale is examined. We are interested especially in the role of hydrogen molecules for formation and evolution of primordial galaxies. Then, formation process of hydrogen…

Astrophysics · Physics 2015-06-24 Hideyuki Kamaya , Hiroyuki Hirashita

Photoionization models so far are unable to account for the high electron temperature Te([O III]) implied by the line ratio [O III]4363A/[O III]5007A in low-metallicity blue compact dwarf galaxies, casting doubts on the assumption of…

Astrophysics · Physics 2009-11-13 D. Pequignot

We analyzed the resolved stellar population of the C component of the extremely metal-poor dwarf galaxy Izw18 in order to evaluate its distance and star formation history as accurately as possible. In particular, we aimed at answering the…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-02 Luc Jamet , Miguel Cervino , Valentina Luridiana , Enrique Perez , T. Yakobchuk

IZw18 is one of the lowest-metallicity star-forming galaxies known at z$\sim$0, considered a unique local analogue of the first galaxies. The origin of its hard ionizing continuum, expected to be a common feature in the early Universe and…

The recent discovery of a galaxy at z=7.3 with undetected optical emission lines and a blue UV to optical continuum ratio in JWST spectroscopy is surprising and needs to be explained physically. Here, we explore two possibilities that could…

Astrophysics of Galaxies · Physics 2024-06-21 A. L. Faisst , T. Morishita

(abridged): Using HST and ground-based optical and NIR imaging data, we investigate whether the blue compact dwarf (BCD) galaxy I Zw 18 possesses an extended low-surface-brightness (LSB) old stellar population underlying its star-forming…

Astrophysics · Physics 2009-11-07 P. Papaderos , Y. I. Izotov , T. X. Thuan , K. G. Noeske , K. J. Fricke , N. G. Guseva , R. F. Green

We present high-resolution radio continuum observations of the nascent starburst in the metal-poor galaxy SBS 0335-052. These radio data were taken with the Very Large Array and include observations at 0.7cm, 1.3cm, 2cm, 3.6cm, and 6cm.…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 K. E. Johnson , L. K. Hunt , A. E. Reines

The decline of star formation in massive low-redshift galaxies, often referred to as quenching, has been attributed to a variety of factors. Some proposals suggest that erupting active galactic nuclei may strip galaxies of their…

Astrophysics of Galaxies · Physics 2015-12-09 Martin Harwit

Context: The earliest stages of high-mass star formation are still poorly characterized. It is also unknown whether the initial conditions vary with environment. Aims: We want to investigate the youngest massive gas clumps in the…

We explore the evolution of the Stellar Mass-Star Formation Rate-Metallicity Relation using a set of 256 COSMOS and GOODS galaxies in the redshift range 1.90 < z < 2.35. We present the galaxies' rest-frame optical emission-line fluxes…

The cosmic star formation histories are evaluated for different minimum masses of the initial halo structures, with allowance for realistic gas outflows. With a minimum halo mass of 10^{7} - 10^{8} M_odot and a moderate outflow efficiency,…

Astrophysics · Physics 2009-09-15 Frederic Daigne , Keith A. Olive , Joe Silk , Felix Stoehr , Elisabeth Vangioni

Massive rotating single stars with an initial metal composition appropriate for the dwarf galaxy I Zw 18 ([Fe/H]=$-$1.7) are modelled during hydrogen burning for initial masses of 9-300 M$_{\odot}$ and rotational velocities of 0-900 km…

Solar and Stellar Astrophysics · Physics 2015-08-26 D. Szécsi , N. Langer , S. -C. Yoon , D. Sanyal , S. de Mink , C. J. Evans , T. Dermine

New integral field spectroscopy has been obtained for IZw18, the nearby lowest-metallicity galaxy considered our best local analog of systems forming at high-z. Here we report the spatially resolved spectral map of the nebular HeII4686…

Astrophysics of Galaxies · Physics 2015-06-23 C. Kehrig , J. M. Vilchez , E. Perez-Montero , J. Iglesias-Paramo , J. Brinchmann , D. Kunth , F. Durret , F. M. Bayo

Massive galaxies in the early Universe have been shown to be forming stars at surprisingly high rates. Prominent examples are dust-obscured galaxies which are luminous when observed at sub-millimeter (sub-mm) wavelengths and which may be…

We investigate the burstiness of star formation and the ionizing efficiency of a large sample of galaxies at $0.7 < z < 1.5$ using HST grism spectroscopy and deep ultraviolet (UV) imaging in the GOODS-N and GOODS-S fields. The star…

We present the stellar metallicities and multi-element abundances (C, Mg, Si, Ca, Ti, Cr, and Fe) of 15 massive (log $M/M_\odot=10.2-11.2$) quiescent galaxies at z=1-3, derived from ultradeep JWST-SUSPENSE spectra. Compared to quiescent…

The abundance of carbon relative to oxygen (C/O) is a promising probe of star formation history in the early universe, as the ratio changes with time due to production of these elements by different nucleosynthesis pathways. We present a…

Spectroscopic long-slit observations of the dwarf Irr galaxy IC 10 were conducted at the 6-m Special Astrophysical Observatory telescope with the SCORPIO focal reducer. The ionized-gas emission spectra in the regions of intense current star…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-23 T. A. Lozinskaya , O. V. Egorov , A. V. Moiseev , D. V. Bizyaev

We present high spatial resolution observations of the blue compact dwarf galaxy IZW18 performed in the Halpha line with a scanning Fabry-Perot interferometer at the CFH telescope. Morphological structure of the galaxy in Halpha and in the…

Astrophysics · Physics 2007-05-23 A. R. Petrosian , J. Boulesteix , G. Comte , D. Kunth , E. Le Coarer

Thanks to their proximity, local starbursts are perfectly suited for high-resolution and sensitivity multiwavelength observations aimed to test our ideas about star formation, evolution of massive stars, physics and chemical evolution of…

Astrophysics · Physics 2007-05-23 A. Aloisi , T. M. Heckman , C. G. Hoopes , C. Leitherer , S. Savaglio , K. R. Sembach