中文
相关论文

相关论文: VLA OH Zeeman Observations of the star forming reg…

200 篇论文

Broad hydroxyl (OH) absorption-lines in the 1667 MHz and 1665 MHz transition towards the central region of NGC 3079 have been observed at high resolution with the European VLBI Network (EVN). Velocity fields of two OH absorption components…

天体物理学 · 物理学 2009-11-10 Y. Hagiwara , H. -R. Kloeckner , W. Baan

Recent observational and theoretical advances have called into question traditional OH maser pumping models in evolved (OH/IR) stars. The detection of excited-state OH lines would provide additional constraints to discriminate amongst these…

We present a detection of a broad Ly-alpha absorber (BLA) with a matching O VI line in the nearby universe. The BLA is detected at z = 0.01028 in the high S/N spectrum of Mrk 290 obtained using the Cosmic Origins Spectrograph. The Ly-alpha…

宇宙学与河外天体物理 · 物理学 2019-08-19 Anand Narayanan , Bart P. Wakker , Blair D. Savage , Brian A. Keeney , J. Michael Shull , John T. Stocke , Kenneth R. Sembach

We present the results of a comprehensive survey using the Arecibo Observatory for Zeeman splitting of OH lines in OH megamasers (OHMs). A total of seventy-seven sources were observed with the Arecibo telescope. Of these, maser emission…

星系天体物理 · 物理学 2013-08-15 James McBride , Carl Heiles

Observations of the QSO HE 0226-4110 (zem = 0.495) with the Cosmic Origins Spectrograph (COS) from 1134 to 1796 {\AA} with a resolution of ~17 km s-1 and signal-to- noise (S/N) per resolution element of 20 to 40 are used to study the…

宇宙学与河外天体物理 · 物理学 2015-06-03 B. Savage , N. Lehner , A. Narayanan

We present three epochs of VLBA observations of Galactic HI absorption toward the quasar 3C~138 with resolutions of 20 mas (~ 10 AU). This analysis includes VLBA data from observations in 1999 and 2002 along with a reexamination of 1995…

天体物理学 · 物理学 2008-11-26 C. L. Brogan , B. A. Zauderer , T. J. Lazio , W. M. Goss , C. D. De Pree , M. D. Fasion

We report on new aspects of the star-forming region S235AB revealed through high-resolution observations at radio and mid-infrared wavelengths. Using the Very Large Array, we carried out sensitive observations of S235AB in the cm continuum…

天体物理学 · 物理学 2009-11-11 Marcello Felli , Fabrizio Massi , Massimo Robberto , Riccardo Cesaroni

We have carried out a multi-species study of a region which has had previous measurements of strong magnetic fields through the CN Zeeman effect in order to to explore the relationship between CN and N$_2$H$^+$, both of which have evidence…

太阳与恒星天体物理 · 物理学 2012-09-03 Nicholas S. Hakobian , Richard M. Crutcher

Observations of young stellar objects (YSOs) in centimeter bands can probe the continuum emission from growing dust grains, ionized winds, and magnetospheric activity, which are intimately connected to the evolution of protoplanetary disks…

We report the detection of a magnetic field on the Of?p star HD108. Spectropolarimetric observations conducted in 2007, 2008 and 2009 respectively with NARVAL@TBL and ESPaDOnS@CFHT reveal a clear Zeeman signature in the average Stokes V…

太阳与恒星天体物理 · 物理学 2015-05-18 F. Martins , J. -F. Donati , W. L. F. Marcolino , J. -C. Bouret , G. A. Wade , C. Escolano , I. D. Howarth

We report the detection and investigate the properties of high-excitation lambda-doubling line emission of hydroxyl (OH) detected towards three asymptotic giant branch (AGB) stars (W Hya, R Dor, and IK Tau) using ALMA. The OH lines are…

太阳与恒星天体物理 · 物理学 2019-03-06 T. Khouri , L. Velilla-Prieto , E. De Beck , W. H. T. Vlemmings , H. Olofsson , B. Lankhaar , J. H. Black , A. Baudry

MHD simulations show that the magnetic field can drive molecular outflows during the formation of massive protostars. The best probe to observationally measure both the morphology and the strength of this magnetic field at scales of 10-100…

太阳与恒星天体物理 · 物理学 2019-03-20 G. Surcis , W. H. T. Vlemmings , H. J. van Langevelde , B. Hutawarakorn Kramer , A. Bartkiewicz

Transit observations of HD 209458b in the stellar Lyman-$\alpha$ (Ly$\alpha$) line revealed strong absorption in both blue and red wings of the line interpreted as hydrogen atoms escaping from the planet's exosphere at high velocities. The…

空间物理 · 物理学 2014-11-26 K. G. Kislyakova , M. Holmström , H. Lammer , P. Odert , M. L. Khodachenko

The giant molecular cloud complex, Sgr B2, was observed with the ISO Long Wavelength Spectrometer over the range 47-197 microns. The ground state rotational transitions of OH lie in the survey range and we have analysed results from the…

天体物理学 · 物理学 2007-05-23 E. T. Polehampton , J. -P. Baluteau , B. M. Swinyard

Lyman- and Werner-band absorption of molecular hydrogen (H$_2$) is detected in $\sim$50% of low redshift ($z<1$) DLAs/sub-DLAs with $N$(H$_2$) > 10$^{14.4}$ cm$^{-2}$. However the true origin(s) of the H$_2$ bearing gas remain elusive. Here…

星系天体物理 · 物理学 2016-06-01 Sowgat Muzahid , Glenn G. Kacprzak , Jane C. Charlton , Christopher W. Churchill

Based on the two epochs EVN archive data from OH line observations of IIZw 096, we confirm that the high-resolution OH emission in this source mainly comes from two spots (OH1 and OH2) of comp D1 of this merging system. We found no…

We present phase-referenced VLBI results on the radio continuum and the OH 18 cm megamaser emission from the Ultra-Luminous Infrared Galaxy, IRAS 17208--0014. The observations were carried out at 1599 MHz using the Very Long Baseline Array,…

天体物理学 · 物理学 2008-11-26 E. Momjian , J. D. Romney , C. L. Carilli , T. H. Troland

We present the largest sample of high-mass star-forming regions observed using submillimetre imaging polarimetry. The data were taken using SCUBA in conjunction with the polarimeter on the JCMT in Hawaii. In total, 16 star forming regions…

天体物理学 · 物理学 2009-11-13 R. L. Curran , A. Chrysostomou

We have serendipitously detected a strong O VI-bearing Lyman limit system at z_abs = 0.3558 toward the QSO J1009+0713 (z_em = 0.456) in our survey of low-redshift galaxy halos with the Hubble Space Telescope's Cosmic Origins Spectrograph.…

宇宙学与河外天体物理 · 物理学 2015-05-27 J. Tumlinson , J. K. Werk , C. Thom , J. D. Meiring , J. X. Prochaska , T. M. Tripp , J. M. O'Meara , M. Okrochkov , K. R. Sembach

Context: Some O stars are suspected to have to have (weak) magnetic fields because of the observed cyclical variability in their UV wind-lines. However, direct detections of these magnetic fields using optical spectropolarimetry have proven…