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相关论文: Tiny HI Clouds in the Local ISM

200 篇论文

The main goal of this analysis is to present a new method to estimate the physical properties of diffuse cloud of atomic hydrogen observed at high Galactic latitude. This method, based on a comparison of the observations with fractional…

天体物理学 · 物理学 2009-11-13 Marc-Antoine Miville-Deschenes , Peter G. Martin

We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source SMM1 and its size is 8' x 8'. The fine structure line emission…

天体物理学 · 物理学 2009-11-07 B. Larsson , R. Liseau , A. B. Men'shchikov

We present HST/GHRS echelle observations of multiple interstellar lines of CI, MgI, CrII, and ZnII towards both stars in the mu Cru binary system. Despite large differences in the profiles of the neutral species, no significant variations…

天体物理学 · 物理学 2009-10-30 J. T. Lauroesch , David M. Meyer , John K. Watson , J. C. Blades

We have used the IRAM 30-m and FCRAO 14-m telescopes to observe the molecular clumps associated with 12 ultracompact (UC) HII regions in the J=6-5, 8-7 and 13-12 rotational transitions of methyl-acetylene (CH3C2H). Under the assumption of…

天体物理学 · 物理学 2009-11-07 F. Fontani , R. Cesaroni , P. Caselli , L. Olmi

We present the results of a large search for intrinsic HI 21 cm and OH 18 cm absorption in 145 compact radio sources in the redshift range 0.02< z <3.8 with the Green Bank Telescope. We re-detect HI 21 cm absorption toward six known…

星系天体物理 · 物理学 2019-11-27 Kathryn Grasha , Jeremy Darling , Alberto Bolatto , Adam K. Leroy , John T. Stocke

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

高能天体物理现象 · 物理学 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

We show 21-cm line profiles in the direction of stars and extragalactic objects, lying projected on high- and intermediate-velocity clouds (HVCs and IVCs). About half of these are from new data obtained with the Effelsberg 100-m telescope,…

天体物理学 · 物理学 2009-11-06 B. P. Wakker , P. M. W. Kalberla , H. van Woerden , K. S. de Boer , M. E. Putman

The high-latitude Galactic H I cloud toward the extragalactic radio source 3C 225 is characterized by very narrow 21 cm emission and absorption indicative of a very low H I spin temperature of about 20 K. Through high-resolution optical…

天体物理学 · 物理学 2009-11-11 David M. Meyer , J. T. Lauroesch , Carl Heiles , J. E. G. Peek , Kyle Engelhorn

We present observations from our continuing studies of the earliest stages of massive star cluster evolution. In this paper, radio observations from the Very Large Array at 0.7cm, 1.3cm, 2cm, 3.6cm, and 6cm are used to map the radio…

天体物理学 · 物理学 2009-11-10 Kelsey E. Johnson , Henry A. Kobulnicky

Large-scale radio continuum surveys provide data to get insights into the physical properties of radio sources. HII regions are prominent radio sources produced by thermal emission of ionised gas around young massive stars. We identify and…

星系天体物理 · 物理学 2019-03-13 X. Y. Gao , P. Reich , L. G. Hou , W. Reich , J. L. Han

We carried out deep and wide-field near- and mid-infrared observations for a sample of 8 bright-rimmed clouds (BRCs). Supplemented with the $Spitzer$ archival data, we have identified and classified 44 to 433 young stellar objects (YSOs)…

太阳与恒星天体物理 · 物理学 2016-05-04 Saurabh Sharma , A. K. Pandey , J. Borissova , D. K. Ojha , V. D. Ivanov , K. Ogura , N. Kobayashi , R. Kurtev , M. Gopinathan , Ram Kesh Yadav

We present a study, done with the Australian LBA, of HI absorption for two compact radio galaxies (PKS 1549-79 and PKS 1814-63). In both the radio galaxies, the HI appears to give us information about the environment in which the radio…

天体物理学 · 物理学 2007-05-23 R. Morganti , T. A. Oosterloo , C. N. Tadhunter , K. A. Wills , A. Tzioumis , J. Reynolds

We report subarcsecond-resolution VLA imaging of four nearby spiral galaxies: IC 342, Maffei II, NGC 2903, and NGC 6946. In each galaxy, compact radio continuum sources are identified in the central ~ 15" x 15" region. These compact sources…

天体物理学 · 物理学 2008-11-26 Chao-Wei Tsai , Jean L. Turner , Sara C. Beck , Lucian P. Crosthwaite , Paul T. P. Ho , David S. Meier , ;

We determine the small-scale structure for a large sample of Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources and a sample of larger radio sources at 327 MHz using the technique of Inter-Planetary Scintillation (IPS)…

天体物理学 · 物理学 2007-05-23 S. Jeyakumar , D. J. Saikia , A. Pramesh Rao , V. Balasubramanian

In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies…

天体物理学 · 物理学 2008-11-26 David E. Hogg , Morton S. Roberts , Martha P. Haynes , Ronald J. Maddalena

We present an empirical dynamical model of the local interstellar medium based on 270 radial-velocity measurements for 157 sight lines toward nearby stars. Physical-parameter measurements (i.e., temperature, turbulent velocity, depletions)…

天体物理学 · 物理学 2007-09-28 Seth Redfield , Jeffrey L. Linsky

In order to investigate the origin of the interstellar turbulence, detailed observations in the CO J=1--0 and 3--2 lines have been carried out in an interacting region of a molecular cloud with an HII region. As a result, several 1,000 to…

Using infrared to (sub)millimeter data from Spitzer, Herschel, the James Clerk Maxwell Telescope, and the IRAM 30-m telescope, we conducted an unbiased survey of the massive dense cores (MDCs) in the Cygnus X molecular cloud complex, aimed…

星系天体物理 · 物理学 2019-02-27 Yue Cao , Keping Qiu , Qizhou Zhang , Yuwei Wang , Bo Hu , Junhao Liu

WSRT observations have provided a first inventory of the incidence of HI 21 cm line absorption associated with AGN at redshifts up to z=1.0. There is a large range in line depths, from tau=0.44 to tau less than 0.001, and a substantial…

天体物理学 · 物理学 2007-05-23 R. C. Vermeulen

We have imaged five compact high-velocity clouds in HI with arcmin angular- and km/s spectral-resolution using the WSRT. Supplementary total-power data, which is fully sensitive to both the cool and warm components of HI, is available for…

天体物理学 · 物理学 2009-11-07 V. de Heij , R. Braun , W. B. Burton