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相关论文: DI in the outer Galaxy

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Galaxy and occupies perhaps a quarter of the volume of the Galactic disk. Decoding the spectrum of the Galactic diffuse ionizing field is of fundamental interest. This can be done via direct measurements of ionization fractions of various…

星系天体物理 · 物理学 2023-03-07 S. R. Kulkarni , Charles Beichman , Michael E. Ressler

HD 140283 is a nearby (V=7.7) subgiant metal-poor star, extensively analysed in the literature. Although many spectra have been obtained for this star, none showed a signal-to-noise (S/N) ratio high enough to enable a very accurate…

太阳与恒星天体物理 · 物理学 2012-11-06 C. Siqueira Mello , B. Barbuy , M. Spite , F. Spite

The Galactic Center and inner disk of the Milky Way contain complex stellar populations obscured by heavy dust extinction. To study their chemical composition, high-resolution near-infrared (near-IR) spectroscopy is necessary. Expanding the…

The amount of deuterium relative to hydrogen (D/H) in clouds with close to primordial abundance seen at high redshift in the spectra of distant quasars currently provides the best estimate of the baryonic density of the Universe. The first…

天体物理学 · 物理学 2009-10-28 Antoinette Songaila , E. Joseph Wampler , Lennox L. Cowie

The primordial deuterium abundance probes fundamental physics during the Big Bang Nucleosynthesis and can be used to infer cosmological parameters. Observationally, the abundance can be measured using absorbing clouds along the lines of…

宇宙学与河外天体物理 · 物理学 2017-05-03 S. Riemer-Sørensen , S. Kotuš , J. K. Webb , K. Ali , V. Dumont , M. T. Murphy , R. F. Carswell

We present new observations of the binary Sirius A / Sirius B performed with HST-GHRS. Two interstellar clouds are detected on this sightline, one of them being identified as the Local Interstellar Cloud (LIC). The interstellar structure of…

天体物理学 · 物理学 2007-05-23 G. Hebrard , C. Mallouris , R. Ferlet , D. Koester , M. Lemoine , A. Vidal-Madjar , D. York

Leo T is the lowest mass gas-rich galaxy currently known and studies of its gas content help us understand how such marginal galaxies survive and form stars. We present deep neutral hydrogen (HI) observations from the Westerbork Synthesis…

星系天体物理 · 物理学 2018-04-18 Elizabeth A. K. Adams , Tom A. Oosterloo

We report the discovery of deuterium absorption in the very metal-poor ([Fe/H] = -2.88) damped Lyman-alpha system at z_abs = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D I absorption lines and the damping wings of…

宇宙学与河外天体物理 · 物理学 2015-06-16 Ryan Cooke , Max Pettini , Regina A. Jorgenson , Michael T. Murphy , Charles C. Steidel

We present observations of the Be II 313.0 nm resonance doublet in 14 halo and old disk stars with metallicities ranging from [Fe/H]=-0.4 to about -3.0 obtained with the CASPEC spectrograph of the ESO 3.6m telescope at a FWHM about 8.6 km/s…

天体物理学 · 物理学 2007-05-23 P. Molaro , P. Bonifacio , F. Castelli , L. Pasquini

The origin of the observed variability of the gas-phase D/H ratio in the local interstellar medium is still debated, and in particular the role of deuterium depletion onto dust grains. Here we extend the study of the relationship between…

天体物理学 · 物理学 2009-11-13 R. Lallement , G. Hebrard , B. Y. Welsh

Neutral hydrogen (HI) is the primary component of the cool interstellar medium (ISM) and is the reservoir of fuel for star formation. Owing to the sensitivity of existing radio telescopes, our understanding of the evolution of the ISM in…

We investigate the properties of the interstellar medium, star formation, and the current-day stellar population in the strongly-lensed star-forming galaxy H-ATLAS J091043.1-000321 (SDP.11), at z = 1.7830, using new Herschel and ALMA…

星系天体物理 · 物理学 2018-11-28 C. Lamarche , A. Verma , A. Vishwas , G. J. Stacey , D. Brisbin , C. Ferkinhoff , T. Nikola , S. J. U. Higdon , J. Higdon , M. Tecza

The total deuterium abundance [D/H] in the universe is set by just two processes: the creation of deuterium in Big Bang Nucleosynthesis at an abundance of [D/H]$=2.58\pm0.13\times10^{-5}$, and its destruction within stellar interiors.…

We have undertaken a survey for HI 21-cm absorption within the host galaxies of z ~ 1.2 - 1.5 radio sources, in the search of the cool neutral gas currently "missing" at z > 1. This deficit is believed to be due to the optical selection of…

宇宙学与河外天体物理 · 物理学 2015-06-12 S. J. Curran , M. T. Whiting , A. Tanna , E. M. Sadler , M. B. Pracy , R. Athreya

We have discovered a third quasar absorption system which is consistent with a low deuterium to hydrogen abundance ratio, D/H = 3.4 times 10^-5. The z ~ 2.8 partial Lyman limit system towards QSO 0130-4021 provides the strongest evidence to…

天体物理学 · 物理学 2009-10-31 David Kirkman , David Tytler , Scott Burles , Dan Lubin , John M. O'Meara

We present the results of deep Lyman limit imaging in four new fields as part of a continuing search for galaxies at $3.0 \le z \le 3.5$. The technique uses a custom broad--band filter set ($U_n G {\cal R}$) designed to isolate objects…

天体物理学 · 物理学 2009-10-28 C. Steidel , M. Pettini , D. Hamilton

We present Herschel-SPIRE Fourier Transform Spectrometer (FTS) and radio follow-up observations of two Herschel-ATLAS (H-ATLAS) detected strongly lensed distant galaxies. In one of the targeted galaxies H-ATLAS J090311.6+003906 (SDP.81) we…

Two groups have independently reported the possible detection of extragalactic deuterium in the absorption spectrum of the same high redshift, low metalicity QSO. Although the high value for the inferred deuterium abundance poses no…

天体物理学 · 物理学 2016-06-08 Gary Steigman

We report a detection in the interstellar medium of an infrared transition within the electronic ground state of the deuterated hydrogen molecule, HD. Through a deep integration with the Short-Wavelength-Spectrometer on ISO, the pure…

天体物理学 · 物理学 2007-05-23 Frank Bertoldi , Ralf Timmermann , Dirk Rosenthal , Siegfried Drapatz , Christopher M. Wright

Leading models of galaxy formation require large-scale energetic outflows to regulate the growth of distant galaxies and their central black holes. However, current observational support for this hypothesis at high redshift is mostly…

宇宙学与河外天体物理 · 物理学 2015-05-14 D. M. Alexander , A. M. Swinbank , I. Smail , R. McDermid , N. Nesvadba