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We present a 93' by 93' map of the area near the Local Group dwarf galaxy LGS 3, centered on an HI cloud 30' away from the galaxy. Previous authors associated this cloud with LGS 3 but relied on observations made with a 36' beam. Our…

天体物理学 · 物理学 2009-11-07 Timothy Robishaw , Joshua D. Simon , Leo Blitz

We have used the Westerbork Synthesis Radio Telescope to detect HI 21cm absorption at $z \sim 0.7645$ in the gravitational lens system towards PMN J0134-0931. The 21cm profile has two broad components, with peak optical depths of $0.047 \pm…

天体物理学 · 物理学 2009-11-10 N. Kanekar , F. H. Briggs

Analysis of interstellar absorption lines observed in high-resolution {\em HST} spectra of nearby stars provides temperatures, turbulent velocities, and kinetic properties of warm interstellar clouds. Previous studies identified 15 warm…

星系天体物理 · 物理学 2022-08-31 Jeffrey L. Linsky , Seth Redfield , Diana Ryder , Adina Chasan-Taber

We present Westerbork Synthesis Radio Telescope HI images, Lovell Telescope multibeam HI wide-field mapping, Wisconsin H-alpha Mapper facility images, William Herschel Telescope longslit echelle CaII observations, and IRAS ISSA 60 and 100…

天体物理学 · 物理学 2009-11-07 J. V. Smoker , L. M. Haffner , F. P. Keenan , R. D. Davies , D. Pollacco

A set of diffuse interstellar clouds in the inner Galaxy within a few hundred pc of the Galactic plane has been observed at an angular resolution of ~1 arcmin combining data from the NRAO Green Bank Telescope and the Very Large Array. At…

星系天体物理 · 物理学 2015-06-15 Yurii Pidopryhora , Felix J. Lockman , John M. Dickey , Michael P. Rupen

We identify 814 discrete HI clouds in 40 dwarf irregular galaxies from the LITTLE THINGS survey using an automated cloud-finding algorithm. The cloud masses range from ~10^3 to 10^7 Msolar, have a surface density averaged over all of the…

星系天体物理 · 物理学 2019-06-05 Deidre A. Hunter , Bruce G. Elmegreen , Clara L. Berger

Observations with the Green Bank Telescope of 21cm HI emission from the high-velocity cloud Complex H suggest that it is interacting with the Milky Way. A model in which the cloud is a satellite of the Galaxy in an inclined, retrograde…

天体物理学 · 物理学 2009-11-07 Felix J. Lockman

We present Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of high, intermediate, and low ion absorption in high-velocity cloud Complex C along the lines of sight toward five active galaxies. Our purpose is to…

We present observations of CO, 13CO and of H2O in the middle and far-infrared taken with the ISO-SWS and ISO-LWS spectrometers toward two positions in the Galactic Center region (Sgr A* and GCS-3). Both ice and gas phase molecules are…

天体物理学 · 物理学 2009-10-31 Andrea Moneti , Jose Cernicharo , Juan Ramon Pardo

Neutral hydrogen 21 cm transition is a useful tracer of the neutral interstellar medium. However, inferring physical condition from the observed 21 cm absorption and/or emission spectra is often not straightforward. One complication in…

星系天体物理 · 物理学 2021-01-13 Atanu Koley , Nirupam Roy

We present new H I 21 cm absorption data and ultraviolet spectroscopy from HST/STIS of the QSO/galaxy pair 3C 232/NGC 3067. The QSO sightline lies near the minor axis and 1.8 arcmin (11 kpc) above the plane of NGC 3067, a nearby luminous…

天体物理学 · 物理学 2009-11-10 Brian A. Keeney , Emmanuel Momjian , John T. Stocke , Chris L. Carilli , Jason Tumlinson

We analyze line-of-sight atomic hydrogen (HI) line profiles of 31 nearby, low-mass galaxies selected from the Very Large Array - ACS Nearby Galaxy Survey Treasury (VLA-ANGST) and The HI Nearby Galaxy Survey (THINGS) to trace regions…

By combining the data from surveys for HI 21-cm absorption at various impact parameters in near-by galaxies, we report an anti-correlation between the 21-cm absorption strength (velocity integrated optical depth) and the impact parameter.…

星系天体物理 · 物理学 2016-04-27 S. J. Curran , S. N. Reeves , J. R. Allison , E. M. Sadler

Recent, high sensitivity, HI observations of nearby spiral galaxies show that their thin `cold' disks are surrounded by thick layers (halos) of neutral gas with anomalous kinematics. We present results for three galaxies viewed at different…

天体物理学 · 物理学 2007-05-23 Filippo Fraternali , Tom Oosterloo , Rense Boomsma , Rob Swaters , Renzo Sancisi

We present a method to determine the spin temperature $T_{\rm S}$ and volume density $n$ of HI gas simultaneously along the tangent-point circle of galactic rotation in the Milky Way by using the least-$\chi^2$ method. The best-fit $T_{\rm…

星系天体物理 · 物理学 2018-05-16 Yoshiaki Sofue

ABSRACT:We show how to use 21-cm emission and absorption studies to estimate the heat inputs to the neutral gas in low pressure environments, such as in outer disks of spiral galaxies, in galactic halos or in intergalactic space. For a…

天体物理学 · 物理学 2009-10-22 Edvige Corbelli , Edwin E. Salpeter

We detect the neutral hydrogen (HI) radial brightness temperature profile in large-scale haloes by stacking 48,430 galaxies selected from the 2dFGRS catalogue onto a set of 21-cm intensity maps obtained with the Parkes radio telescope,…

宇宙学与河外天体物理 · 物理学 2020-10-14 Denis Tramonte , Yin-Zhe Ma

Six examples of the compact, isolated high-velocity HI clouds (CHVCs) identified by Braun and Burton (1999) have been imaged with the WSRT. The 65 confirmed objects in this class define a dynamically cold system, with a global minimum for…

天体物理学 · 物理学 2007-05-23 Robert Braun , Butler Burton

We have detected absorption lines from the High Velocity Cloud Complex WB in the spectrum of the star HE1048+0231. This detection sets an upper distance limit to the cloud of 8.8^{+2.3}_{-1.3} kpc. Non-detection (at >4 sigma confidence) in…

天体物理学 · 物理学 2009-11-11 C. Thom , M. E. Putman , B. K. Gibson , N. Christlieb , C. Flynn , T. C. Beers , R. Wilhelm , Y. S. Lee