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Related papers: VLA HI Zeeman Observations Toward the W49 Complex

200 papers

We present the results of a VLA and WSRT search for HI emission from the vicinity of seven nearby clouds, which were observed in Lya absorption with HST toward Mrk335, Mrk501 and PKS2155-304. We searched a volume of 40' x 40' x 1000 km/s.…

We analyzed high angular resolution 45.5 GHz images of the W49 North massive star forming region obtained in 1998 and 2016 with the Very Large Array. Most of the ultracompact HII regions show no detectable changes over the time interval of…

Solar and Stellar Astrophysics · Physics 2020-03-04 Luis F. Rodriguez , Roberto Galvan-Madrid , Joel Sanchez-Bermudez , Christopher G. De Pree

The W49 region hosts two bright radio sources: the star forming region W49A and the supernova remnant W49B. The 10^6 M_odot Giant Molecular Cloud W49A is one of the most luminous giant radio HII regions in our Galaxy and hosts several…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Francois Brun , Mathieu de Naurois , Werner Hofmann , Svenja Carrigan , Arache Djannati-Ataï , Stefan Ohm

We present OH and H I Zeeman observations of the NGC 6334 complex taken with the Very Large Array. The OH absorption profiles associated with the complex are relatively narrow (del-v_FWHM ~ 3 km s^1) and single-peaked over most of the…

Astrophysics · Physics 2009-10-31 A. P. Sarma , T. H. Troland , D. A. Roberts , R. M. Crutcher

M82 is one of the best studied starburst galaxies in the local universe, and is consequently a benchmark for studying star formation feedback at both low and high redshift. We present new VLA HI observations that reveal the cold gas…

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…

Aims: we studied the global distribution and kinematics of the extra-planar neutral gas in the Milky Way. Methods: we built 3D models for a series of Galactic HI layers, projected them for an inside view, and compared them with the…

Astrophysics of Galaxies · Physics 2015-05-20 Antonino Marasco , Filippo Fraternali

The baryons inside high-redshift halos with virial temperatures above T=10^4 K cool radiatively as they condense inside dark matter potential wells. We show that the release of the gravitational binding energy, over the halo assembly…

Astrophysics · Physics 2009-10-31 Zoltan Haiman , Marco Spaans , Eliot Quataert

Observations of the neutral atomic hydrogen (HI) in the nuclear starburst galaxy NGC 4945 with MeerKAT are presented. We find a large amount of halo gas, previously missed by HI observations, accounting for 6.8% of the total HI mass. This…

A mosaic of six HI line observations with the Australia Telescope Compact Array is used to search for intergalactic gas in the NGC 1808 group of galaxies. Within the field of view of about 1.4 deg x 1.2 deg, no emission from intergalactic…

Astrophysics · Physics 2009-11-06 Michael Dahlem , Matthias Ehle , Stuart D. Ryder

We present deep HI observations of the compact high-velocity cloud HVC125+41-207 using the 100-m Effelsberg telescope. Our goal was in particular to study the warm neutral medium (WNM) in detail. The Effelsberg data reveal a two phase…

Astrophysics · Physics 2009-11-06 C. Bruens , J. Kerp , A. Pagels

The Wisconsin H-Alpha Mapper (WHAM) Northern Sky Survey is revealing that many intermediate-velocity (|v_LSR| <= 100 km/s) neutral clouds and complexes have an associated ionized component. We present the first map of the H-Alpha emission…

Astrophysics · Physics 2009-11-06 L. M. Haffner , R. J. Reynolds , S. L. Tufte

Optical emission lines provide an important new window on the HVCs. Recent studies of the H-alpha line reveal that ionized gas is pervasively associated with the neutral hydrogen in HVCs. The Wisconsin H-Alpha Mapper (WHAM) instrument has…

Astrophysics · Physics 2007-05-23 S. L. Tufte , R. J. Reynolds , L. M. Haffner

The massive and luminous star-forming region W49A is a well known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical…

Astrophysics of Galaxies · Physics 2015-05-20 Z. Nagy , F. F. S. van der Tak , G. A. Fuller , R. Plume

We present a study of diffuse extended ionised gas toward three clouds located in the Galactic Centre (GC). One line of sight (LOS) is toward the 20 km s$^{-1}$ cloud (LOS$-$0.11) in the Sgr A region, another LOS is toward the 50 km…

In this study, we analyze molecular gas formation in neutral atomic hydrogen (HI) clouds using the latest CO data obtained from the four-beam receiver system on a 45-m telescope (FOREST) unbiased Galactic plane imaging survey with the…

We present the results of Suzaku observation of the radio halo cluster Abell 2319. The metal abundance in the central cool region is found to be higher than the surrounding region, which was not resolved in the former studies. We confirm…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Chika Sugawara , Motokazu Takizawa , Kazuhiro Nakazawa

within 24 lines with 80 characters) We present ^12CO (1-0) observations in the central 4.5 kpc (1 arcmin) of the Halpha/Radio lobe galaxy NGC 3079 with the Nobeyama Millimeter Array. The molecular gas shows four components: a main disk,…

Astrophysics · Physics 2009-11-07 J. Koda , Y. Sofue , K. Kohno , H. Nakanishi , S. Onodera , S. K. Okumura , Judith A. Irwin

The HCN, HCO+, and HNC molecules are commonly used as tracers of dense star-forming gas in external galaxies, but such observations are spatially unresolved. Reliably inferring the properties of galactic nuclei and disks requires detailed…

Astrophysics of Galaxies · Physics 2015-05-20 Helen Roberts , Floris van der Tak , Gary Fuller , René Plume , Estelle Bayet

We present a joint analysis of HI absorption Zeeman measurements and the morphology of filamentary HI emission to investigate the three-dimensional structure of the magnetic field in the diffuse neutral interstellar medium (ISM). Our…

Astrophysics of Galaxies · Physics 2025-08-28 Marta Nowotka , Susan E. Clark , Blakesley Burkhart , Laura Fissel , Tao-Chung Ching , Timothy Robishaw , Carl Heiles