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Related papers: Extremely Metal-Poor Galaxies: The HI Content

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We have analyzed bibliographical observational data and theoretical predictions, in order to probe the environment in which extremely metal-poor dwarf galaxies (XMPs) reside. We have assessed the HI component and its relation to the optical…

Astrophysics of Galaxies · Physics 2015-06-23 M. E. Filho , J. Sánchez Almeida , C. Muñoz-Tuñón , S. E. Nuza , F. Kitaura , S. Heß

Extremely metal-poor (XMP) galaxies are defined to have gas-phase metallicity smaller than a tenth of the solar value (12 + log[O/H] < 7.69). They are uncommon, chemically and possibly dynamically primitive, with physical conditions…

Extremely metal-poor galaxies (XMPGs) at relatively low redshift are excellent laboratories for studying galaxy formation and evolution in the early universe. Much effort has been spent on identifying them from large-scale spectroscopic…

The goal of this study is to measure parameters of the integrated HI emission for twenty-two dwarf galaxies with oxygen abundance 12+log(O/H) in the range of 7.42 to 7.65, which are representatives of the eXtremely Metal-Deficient (XMD)…

Astrophysics · Physics 2009-11-13 S. A. Pustilnik , J. -M. Martin

Extremely metal poor (XMP) galaxies are known to be very rare, despite the large numbers of low-mass galaxies predicted by the local galaxy luminosity function. This paper presents a sub-sample of galaxies that were selected via a…

Astrophysics of Galaxies · Physics 2015-06-23 Bethan L. James , Sergey Koposov , Daniel P. Stark , Vasily Belokurov , Max Pettini , Edward W. Olszewski

The extremely metal-poor (XMP) galaxies analyzed in a previous paper have large star-forming regions with a metallicity lower than the rest of the galaxy. Such a chemical inhomogeneity reveals the external origin of the metal-poor gas…

Extremely metal-poor star-forming galaxies (XMPs) represent one of our only laboratories for study of the low-metallicity stars we expect to encounter at early epochs. But as our understanding of the $z>6$ universe has improved, it has…

Astrophysics of Galaxies · Physics 2019-01-16 Peter Senchyna , Daniel P. Stark

Nearby extremely metal-poor galaxies (XMPs) allow us to study primitive galaxy formation and evolution in greater detail than is possible at high redshift. This work, for the first time, promotes the use of convolutional neural networks…

Astrophysics of Galaxies · Physics 2025-02-04 Ting-Yun Cheng , Ryan J. Cooke

Local extremely metal-poor (XMP) galaxies are of particular astrophysical interest since they allow us to look into physical processes characteristic of the early Universe, from the assembly of galaxy disks to the formation of stars in…

Astrophysics of Galaxies · Physics 2017-02-01 J. Sanchez Almeida , M. E. Filho , C. Dalla Vecchia , E. D. Skillman

We carry out a systematic search for extremely metal poor (XMP) galaxies in the spectroscopic sample of Sloan Digital Sky Survey (SDSS) data release 7 (DR7). The XMP candidates are found by classifying all the galaxies according to the form…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. B. Morales-Luis , J. Sanchez Almeida , J. A. L. Aguerri , C. Munoz-Tunon

Extremely metal-poor (XMP) galaxies are systems with gas-phase oxygen abundances below $\sim$5% Solar metallicity (12+log(O/H)$\le$7.35). These galaxies populate the metal-poor end of the mass-metallicity and luminosity-metallicity…

Extremely metal-poor (XMP) galaxies are low-mass, star-forming galaxies with gas-phase oxygen abundances below 12+log(O/H) = 7.35 (~1/20 Zsun). Galaxy evolution scenarios suggest three pathways to form an XMP: (1) secular evolution at low…

We present and discuss the results of the Giant Metrewave Radio Telescope (GMRT) HI 21-cm line mapping for five isolated low-mass (M_bary ~(2--8)*10^7 Mo) eXtremely Metal Poor (XMP) dwarfs [12+log(O/H)=7.13-7.28], selected from the Nearby…

Astrophysics of Galaxies · Physics 2024-08-05 Sushma Kurapati , Simon A. Pustilnik , Evgeniya S. Egorova

The three-dimensional (3-D) shape of a galaxy inevitably is tied to how it has formed and evolved and to its dark matter halo. Local extremely metal-poor galaxies (XMPs; defined as having an average gas-phase metallicity < 0.1 solar) are…

Astrophysics of Galaxies · Physics 2019-09-25 J. Putko , J. Sanchez Almeida , C. Munoz-Tunon , A. Asensio Ramos , B. G. Elmegreen , D. M. Elmegreen

Low-metallicity galaxies may provide key insights into the evolutionary history of galaxies. Galaxies with strong emission lines and high equivalent widths (rest-frame EW(H-beta) > 30 A) are ideal candidates for the lowest metallicity…

Astrophysics of Galaxies · Physics 2022-09-13 Isaac H. Laseter , Amy J. Barger , Lennox L. Cowie , Anthony J. Taylor

Extremely metal-poor stars are intrinsically rare, but emerging methods exist to accurately classify them from all-sky Gaia XP low-resolution spectra. To assess their overall accuracy for targeting metal-poor stars, we present a…

Solar and Stellar Astrophysics · Physics 2026-01-30 Riley Thai , Andrew R. Casey , Alexander Ji , Vedant Chandra , Hans-Walter Rix

We present Giant Metrewave Radio Telescope (GMRT) observations for three (viz., DDO 68, SDSS J2104-0035 and UGC 772) of the six most metal-deficient actively star-forming galaxies known. Although there is a debate as to whether these…

Astrophysics · Physics 2009-11-13 Ekta , Jayaram N. Chengalur , S. A. Pustilnik

The search for chemically unevolved galaxies remains prevalent in the nearby Universe, mostly because these systems provide excellent proxies for exploring in detail the physics of high-z systems. The most promising candidates are extremely…

(abridged) We present 8.2m VLT spectroscopic observations of 28 HII regions in 16 emission-line galaxies and 3.6m ESO telescope spectroscopic observations of 38 HII regions in 28 emission-line galaxies. These emission-line galaxies were…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-30 N. G. Guseva , P. Papaderos , H. T. Meyer , Y. I. Izotov , K. J. Fricke
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