中文
相关论文

相关论文: Epsilon Canis Majoris: The Brightest EUV Source wi…

200 篇论文

The structure and properties of the diffuse interstellar medium (ISM) on small scales, sub-au to 1 pc, are poorly understood. We compare interstellar absorption-lines, observed towards a selection of O- and B-type stars at two or more…

We report on the detection of Main Sequence stars belonging to the recently identified Canis Major galaxy in a field located at ~ 4.2 deg from the center of the stellar system. With Main Sequence fitting we obtain a distance modulus…

天体物理学 · 物理学 2009-11-10 M. Bellazzini , R. Ibata , L. Monaco , N. Martin , M. J. Irwin , G. F. Lewis

We report the first detection of extended neutral hydrogen (HI) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z~0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at z_QSO = 1.676 as…

星系天体物理 · 物理学 2017-09-20 Fakhri S. Zahedy , Hsiao-Wen Chen , Michael Rauch , Ann Zabludoff

The strongest absorption features with the lower-level excitation potentials $\chi_{\rm low}<1$ eV are found to be split in the high-resolution optical spectra of the post-AGB star V354 Lac taken in 2007--2008. Main parameters,…

太阳与恒星天体物理 · 物理学 2015-05-13 V. G. Klochkova , V. E. Panchuk , N. S. Tavolganskaya

We study the interstellar medium in a sample of 27 high-redshift quasar host galaxies at z>6, using the [CII] 158um emission line and the underlying dust continuum observed at ~1kpc resolution with ALMA. By performing uv-plane spectral…

Moderate and high-resolution measurements (R ~ 40,000) of interstellar resonance lines of D I, C II, N I, O I, Al II, and Si II (light ions) are presented for all available observed targets located within 100 pc which also have…

天体物理学 · 物理学 2009-11-10 Seth Redfield , Jeffrey L. Linsky

We identified a peculiar proximate sub-damped Lya absorption system (sub-DLA) at z=3.234 with a neutral hydrogen column density of $N_{H} =10^{19.70\pm0.15}~\rm cm^{-2}$ toward the quasar SDSS J125903.26+621211.5 in two epoch optical…

星系天体物理 · 物理学 2018-08-29 Xiang Pan , Shaohua Zhang , Hongyan Zhou , Xiaoyi Xie , Xiheng Shi , Peng Jiang , Ning Jiang , Weimin Yuan

We performed spectroscopic analyses of five local compact star-forming galaxies (CSFGs) with extremely high [OIII]/[OII] (O$_{32}$) ratios ($>20$). These targets remarkably share similar properties with high-redshift CIV emitters at $z>6$:…

星系天体物理 · 物理学 2024-09-19 Intae Jung , Swara Ravindranath , Anne E. Jaskot , Henry C. Ferguson , Bethan L. James

We report a deep Giant Metrewave Radio Telescope (GMRT) search for Galactic H{\sc i} 21cm absorption towards the quasar B0438$-$436, yielding the detection of wide, weak H{\sc i} 21cm absorption, with a velocity-integrated H{\sc i} 21cm…

We present results from an extensive HST spectroscopic search for UV absorption lines in the spectrum of the quasar B2~1028+313, which is associated with the central dominant galaxy in the cluster Abell~1030 ($z=0.178$). This is one of the…

天体物理学 · 物理学 2009-10-30 A. M. Koekemoer , C. P. O'Dea , S. A. Baum , C. L. Sarazin , F. N. Owen , M. J. Ledlow

We present 2 - 5 micron adaptive optics (AO) imaging and polarimetry of the famous hypergiant stars IRC +10420 and VY Canis Majoris. The imaging polarimetry of IRC +10420 with MMT-Pol at 2.2 micron resolves nebular emission with intrinsic…

太阳与恒星天体物理 · 物理学 2015-05-19 Dinesh P. Shenoy , Terry J. Jones , Chris Packham , Enrique Lopez-Rodriguez

CONTEXT: Accurate physical properties of eclipsing stars provide important constraints on models of stellar structure and evolution, especially when combined with spectroscopic information on their chemical composition. Empirical…

太阳与恒星天体物理 · 物理学 2015-06-03 G. Torres , J. V. Clausen , H. Bruntt , A. Claret , J. Andersen , B. Nordstrom , R. P. Stefanik , D. W. Latham

The Lyman-alpha emission line dominates the far-ultraviolet spectra of late-type stars and is a major source for photodissociation of important molecules including H2O, CH4, and CO2 in exoplanet atmospheres. The incident flux in this line…

太阳与恒星天体物理 · 物理学 2015-06-12 Jeffrey L. Linsky , Kevin France , Tom Ayres

Unidentified extreme UV sources, detected in the {\it EUVE} and {\it ROSAT} WFC all-sky surveys, could be isolated old neutron stars, accreting material from the ISM. The closest neutron stars, that are located in the local ISM bubble of…

天体物理学 · 物理学 2016-06-08 Amotz Shemi

C$^+$ is a critical constituent of many regions of the interstellar medium, as it can be a major reservoir of carbon and, under a wide range of conditions, the dominant gas coolant. Emission from its 158$\mu$m fine structure line is used to…

星系天体物理 · 物理学 2019-08-19 Laurent Wiesenfeld , Paul F. Goldsmith

The complex structure of gas, metals, and dust in the interstellar and circumgalactic medium (ISM and CGM, respectively) in star-forming galaxies can be probed by Ly$\alpha$ emission and absorption, low-ionization interstellar (LIS) metal…

We report an accurate distance of d = 10+/-2.5kpc to the high-velocity cloud Complex C. Using high signal-to-noise Keck/HIRES spectra of two horizontal-branch stars, we have detected CaII K absorption lines from the cloud. Significant…

天体物理学 · 物理学 2009-11-13 C. Thom , J. E. G. Peek , M. E. Putman , Carl Heiles , K. M. G. Peek , R. Wilhelm

We discuss physical conditions in Galactic neutral hydrogen based on deep, high velocity resolution interferometric HI 21 cm absorption spectroscopy towards 33 compact extra-galactic radio sources. The HI 21 cm optical depth spectra have…

星系天体物理 · 物理学 2014-07-30 Nirupam Roy , Nissim Kanekar , Jayaram N. Chengalur

Low mass, low metallicity galaxies at low to moderate ($z\lesssim3$) redshifts offer the best opportunity for detailed examination of the interplay between massive stars, ionizing radiation and gas in sources similar to those that likely…

星系天体物理 · 物理学 2019-10-16 Dawn K. Erb , Danielle A. Berg , Matthew W. Auger , David L. Kaplan , Gabriel Brammer , Max Pettini

Our objectives are to determine the properties of the interstellar medium (ISM) and of star-formation in typical star-forming galaxies at high redshift. Following up on our previous multi-wavelength observations with HST, Spitzer, Herschel,…