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Related papers: First stellar spectroscopy in Leo P

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We present sensitive CO (J = 1 - 0) emission line observations of three metal-poor dwarf irregular galaxies Leo P (Z ~ 3% Z_Solar), Sextans A (Z ~ 7.5% Z_Solar), and Sextans B (Z ~ 7.5% Z_Solar), all obtained with the Combined Array for…

Context. The study of old, metal-poor stars deepens our knowledge on the early stages of the universe. In particular, the study of these stars gives us a valuable insight into the masses of the first massive stars and their emission of…

Solar and Stellar Astrophysics · Physics 2021-10-04 A. Matas Pinto , M. Spite , E. Caffau , P. Bonifacio , L. Sbordone , T. Sivarani , M. Steffen , F. Spite , P. Francois , P. Di Matteo

We present a study of the evolved stellar populations in the dwarf spheroidal galaxy LeoII, based on JHKs observations obtained with the near-infrared array WFCAM at the UKIRT telescope. Combining the new data with optical data, we derived…

Astrophysics · Physics 2009-06-23 M. Gullieuszik , E. V. Held , L. Rizzi , L. Girardi , P. Marigo , Y. Momany

We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars…

We have studied Leo A - the isolated and extremely gas rich dwarf irregular galaxy of very low stellar mass and metallicity. Ages of the stellar populations in Leo A are ranging from ~10 Myr to ~10 Gyr. Here we report the discovery of an…

We use previously-published moderate-resolution spectra in combination with stellar atmosphere models to derive the first measured chemical abundance ratios in the Leo II dSph galaxy. We find that for spectra with SNR > 24, we are able to…

Astrophysics · Physics 2009-11-13 Matthew Shetrone , Michael H. Siegel , David O. Cook , Tammy Bosler

We carried out a wide-field V, I imaging survey of the Local Group dwarf spheroidal galaxy Leo II using the Subaru Prime Focus Camera on the 8.2-m Subaru Telescope. The survey covered an area of 26.67 x 26.67 arcmin^2, far beyond the tidal…

The oxygen abundances for four dwarf spiral galaxies have been determined using long-slit spectroscopy. The abundances of these galaxies have not previously reported in the literature. Several HII regions were detected in each galaxy. The…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-01 A. M. Hidalgo-Gamez , D. Ramirez-Fuentes , J. J. Gonzalez

We describe the optical properties of a sample of 101 gas-rich field dwarf galaxies found on PSS-II (Second Palomar Sky Survey) plates, most newly discovered as part of a survey to investigate the clustering properties of dwarf galaxies…

Astrophysics · Physics 2009-10-28 R. A. Pildis , J. M. Schombert , J. Eder

We present chemical abundance determinations of two H II regions in the dIrr galaxy Leo A, from GTC OSIRIS long-slit spectra. Both H II regions are of low excitation and seem to be ionised by stars later than O8V spectral type. In one of…

Astrophysics of Galaxies · Physics 2018-08-29 Francisco Ruiz-Escobedo , Miriam Peña , Liliana Hernández-Martínez , Jorge García-Rojas

We report the discovery and spectroscopic confirmation of an ultra-faint Milky Way (MW) satellite in the constellation of Leo. This system was discovered as a spatial overdensity of resolved stars observed with Dark Energy Camera (DECam)…

Spectra that cover wavelengths from 0.6 to 1.1um are used to examine the behavior of emission and absorption features in a contiguous 22 x 300 arcsec region centered on the nearby dwarf galaxy NGC 55. Based on the relative strengths of…

Astrophysics of Galaxies · Physics 2019-08-07 T. J. Davidge

(abridged) We present deep spectroscopy of a large sample of low-metallicity emission-line galaxies. The main goal of this study is to derive element abundances in these low-metallicity galaxies. We analyze 121 VLT spectra of HII regions in…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-08 N. G. Guseva , Y. I. Izotov , G. Stasinska , K. J. Fricke , C. Henkel , P. Papaderos

We present Giant Meterwave Radio Telescope (GMRT) and Westerbork ynthesis Radio Telescope (WSRT) observations of the recently discovered Local Group dwarf galaxy, Leo T. The peak HI column density is measured to be 7x10^20 cm^-2, and the…

We report new observations of SL2SJ021737-051329, a lens system consisting of a bright arc at z=1.84435, magnified ~17x by a massive galaxy at z=0.65. SL2SJ0217 is a low-mass (M <10^9 M*), low-metallicity (Z~1/20 Z*) galaxy, with extreme…

Astrophysics of Galaxies · Physics 2018-06-27 Danielle A. Berg , Dawn K. Erb , Matthew W. Auger , Max Pettini , Gabriel B. Brammer

Context. Late O-type stars at luminosities $\log L/L_\odot \lesssim 5.2$ show weak winds with mass-loss rates lower than 10$^{-8} M_\odot$ yr$^{-1}$. This implies that their photospheric layers are not strongly affected by the stellar wind.…

Solar and Stellar Astrophysics · Physics 2023-03-08 Patrick Aschenbrenner , Norbert Przybilla , Keith Butler

We have used high-resolution, high-S/N ratio spectra from the UVES spectrograph at the ESO VLT telescope. Long-term radial-velocity measurements and broad-band photometry allow us to determine improved orbital elements and stellar…

A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) to deduce details about star formation in nearby disk galaxies selected with no bias to optical surface brightness…

Astrophysics · Physics 2009-11-11 J. F. Helmboldt , R. A. M. Walterbos , G. D. Bothun , K. O'Neil

We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS…

Astrophysics · Physics 2010-10-28 Evan N. Kirby , Joshua D. Simon , Marla Geha , Puragra Guhathakurta , Anna Frebel

Isolated, low-mass galaxies provide the opportunity to assess the impact of reionization on their star formation histories (SFHs) without the ambiguity of environmental processes associated with massive host galaxies. There are very few…