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

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We present the first resolved study of the radio continuum properties of I Zw 18, the dwarf galaxy with the lowest known nebular metal abundance in the local universe. New Very Large Array radio continuum images at 20 and 3.6 cm are…

Astrophysics · Physics 2009-11-10 John M. Cannon , Fabian Walter , Evan D. Skillman , Liese van Zee

We report results from near-infrared imaging of IZw18, the most metal-poor galaxy in the local universe with NICMOS on board the Hubble Space Telescope (HST). Observations were obtained in the broad F205W filter ($\sim$ K) and in the…

Astrophysics · Physics 2009-11-10 G. Ostlin , M. Mouhcine

The extent to which star formation varies in galaxies with low masses, low metallicities, and high star formation rate surface densities is not well-constrained. To gain insight into star formation under these physical conditions, this…

Astrophysics of Galaxies · Physics 2015-06-18 Amanda A. Kepley , Amy E. Reines , Kelsey E. Johnson , Lisa May Walker

The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor ($Z \sim 3% Z_{\sun}$) star-forming galaxies in the local Universe. Its evolutionary status has sparked debate within the astronomical community. We aim to investigate the…

The first galaxies contain stars born out of gas with little or no metals. The lack of metals is expected to inhibit efficient gas cooling and star formation but this effect has yet to be observed in galaxies with oxygen abundance relative…

Astrophysics of Galaxies · Physics 2014-10-22 Yong Shi , Lee Armus , George Helou , Sabrina Stierwalt , Yu Gao , Junzhi Wang , Zhi-Yu Zhang , Qiusheng Gu

I Zw 18 is a prototype Blue Compact Dwarf (BCD), characterized by a strong starburst and extremely low metallicity (Z ~ 0.02 Zsun). It has long been considered a candidate young galaxy in the Local Universe, but recent studies indicate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Federico Lelli , Marc Verheijen , Filippo Fraternali , Renzo Sancisi

The metal deficient starburst galaxy IZw18 has been observed with FUSE in a search for H2 molecules. The spectrum obtained with an aperture covering the full galaxy shows no absorption lines of diffuse H2 at the radial velocity of the…

We present a FUSE spectroscopic study of the nearby gas--rich, metal--deficient blue compact dwarf (BCD) galaxy IZw 36. Atomic hydrogen and many metal lines are observed in absorption against the stellar continuum of young, massive stars…

In this paper we present some results of numerical simulations concerning the development of galactic winds in starburst galaxies. In particular, we focus on a galaxy similar to IZw18, the most metal-poor galaxy locally known. We compute…

Astrophysics · Physics 2007-05-23 S. Recchi , F. Matteucci , A. D'Ercole

In this paper we present some results concerning the study of the development of galactic winds in blue compact galaxies. In particular, we model a situation very similar to that of the galaxy IZw18, the most metal poor and unevolved galaxy…

Astrophysics · Physics 2016-11-03 F. Matteucci , S. Recchi

The blue compact dwarf galaxy I Zw 18 is one of the most metal poor systems known in the local Universe (12 + log(O/H) $=$ 7.17). In this work we study I Zw 18 using data from {\it Spitzer}, {\it Herschel Space Telescope} and IRAM Plateau…

Hubble Space Telescope (HST) colour - magnitude diagrams in B, V and R along with long-slit Multiple Mirror Telescope (MMT) spectrophotometric data are used to investigate the evolutionary status of the nearby blue compact dwarf (BCD)…

Astrophysics · Physics 2007-05-23 Y. I. Izotov , P. Papaderos , T. X. Thuan , K. J. Fricke , C. B. Foltz , N. G. Guseva

We have obtained low-resolution near infrared spectra of three QSOs at 5.7 < z < 6.3 using the NICMOS instrument of the Hubble Space Telescope. The spectra cover the rest-frame ultraviolet emission of the objects between lambda_rest ~ 1600A…

Astrophysics · Physics 2009-11-07 Wolfram Freudling , Michael R. Corbin , Kirk T. Korista

Long-slit Keck II, 4m Kitt Peak, and 4.5m MMT spectrophotometric data are used to investigate the stellar population and the evolutionary status of I Zw 18C, the faint C component of the nearby blue compact dwarf galaxy I Zw 18. Hydrogen…

Stellar wind mass loss is often assumed to depend on their metallicity $Z$. Therefore, evolutionary models of massive stars at lower $Z$ are able to retain more of their H-rich layers and evolve into brighter cool supergiants (cool SGs;…

Solar and Stellar Astrophysics · Physics 2026-03-13 Abel Schootemeijer , Ylva Götberg , Norbert Langer , Giacomo Bortolini , Alec S. Hirschauer , Lee Patrick

We present results from new deep HST/ACS photometry of I Zw 18, the most metal-poor blue compact dwarf galaxy in the nearby universe. It has been previously argued that this is a very young system that started forming stars only < 500 Myr…

I review the observational characteristics of intermediate-to-high redshift star forming galaxies, including their star formation rates, dust extinctions, ISM kinematics, and chemical compositions. I present evidence that the mean rate of…

Astrophysics · Physics 2007-05-23 Chip Kobulnicky

We present new WFPC2 narrow band imaging of the blue compact dwarf galaxy I Zw 18, which is host to the lowest-metallicity HII regions known. Images at H-alpha and H-beta are combined with archival broad band images to allow the study of…

Astrophysics · Physics 2009-11-07 John M. Cannon , Evan D. Skillman , Donald R. Garnett , Reginald J. Dufour

We present new V and I-band HST/ACS photometry of I Zw 18, the most metal-poor blue compact dwarf (BCD) galaxy in the nearby universe. It has been argued in the past that I Zw 18 is a very young system that started forming stars only < 500…

We present V and I photometry of the resolved stars in the most metal-deficient blue compact dwarf galaxy known, I Zw 18 (Zsun/50), using Hubble Space Telescope/Advanced Camera for Surveys (ACS) images, the deepest ones ever obtained for…

Astrophysics · Physics 2009-11-10 Y. I. Izotov , T. X. Thuan