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相关论文: A VLA search for young protostars embedded in dens…

200 篇论文

Context. The different theoretical models concerning the formation of high-mass stars make distinct predictions regarding their progenitors, i.e. the high-mass prestellar cores. However, so far no conclusive observation of such objects has…

星系天体物理 · 物理学 2021-06-30 E. Redaelli , S. Bovino , A. Giannetti , G. Sabatini , P. Caselli , F. Wyrowski , D. R. G. Schleicher , D. Colombo

We report a 0.2" resolution, 15 GHz survey of a sample of 48 low-luminosity active galactic nuclei with the Very Large Array. Compact radio emission has been detected in 57% (17 of 30) of LINERs and low-luminosity Seyferts, at least 15 of…

天体物理学 · 物理学 2009-10-31 Neil M. Nagar , Heino Falcke , Andrew S. Wilson , Luis C. Ho

We present results from the Spitzer Space Telescope and molecular line observations of 9 species toward the dark cloud L43. The Spitzer images and molecular line maps suggest it has a starless core and a Class I protostar evolving in the…

星系天体物理 · 物理学 2014-11-20 Jo-Hsin Chen , Neal J. Evans , Jeong-Eun Lee , Tyler L. Bourke

Protostellar jets provide valuable insight into the evolutionary stage and formation history of star-forming cores in their earliest phases. We investigated the inner envelope structures of three extremely young protostars, selected for…

We investigate the young stellar population in the Vela Molecular Ridge, Cloud-D (VMR-D), a star forming (SF) region observed by both Spitzer/NASA and Herschel/ESA space telescope. The point source, band-merged, Spitzer-IRAC catalog…

太阳与恒星天体物理 · 物理学 2015-06-23 F. Strafella , D. Lorenzetti , T. Giannini , D. Elia , Y. Maruccia , B. Maiolo , F. Massi , L. Olmi , S. Molinari , S. Pezzuto

Aims. We selected two radio quasars (J1036+1326 and J1353+5725) based on their 1.4-GHz radio structure, which is dominated by a bright central core and a pair of weaker and nearly symmetric lobes at ~10" angular separation. They are…

宇宙学与河外天体物理 · 物理学 2010-12-15 D. Cseh , S. Frey , Z. Paragi , L. I. Gurvits , K. E. Gabanyi

We present the detection of compact radio structures of fourteen radio-loud narrow line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array observations at 5 GHz, which were performed in 2013. While 50\% of the sources of our sample…

星系天体物理 · 物理学 2015-10-14 Minfeng Gu , Yongjun Chen , S. Komossa , Weimin Yuan , Zhi-Qiang Shen , Kiyoaki Wajima , Hongyan Zhou , J. A. Zensus

High-mass prestellar cores are extremely rare. The search for such objects has long been hindered by small sample sizes, leading to large uncertainties in their lifetimes and the conditions in which high-mass stars ($> 8\,M_{\odot}$) form.…

We describe an observational program aimed at understanding the radio emission from distant, rapidly evolving galaxy populations. These observations were carried out at 1.4 and 8.5 GHz with the VLA centered on the Hubble Deep Field,…

天体物理学 · 物理学 2009-10-31 E. A. Richards

We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al.…

天体物理学 · 物理学 2009-11-06 C. L. Carilli , F. Bertoldi , A. Omont , P. Cox , R. G. McMahon , K. G. Isaak

Thirteen dwarf galaxies have recently been found to host radio-selected accreting massive black hole (MBH) candidates, some of which are ``wandering" in the outskirts of their hosts. We present 9 GHz Very Long Baseline Array (VLBA)…

Barnard 59 and Lupus 1 are two nearby star-forming regions visible from the southern hemisphere. In this manuscript, we present deep ($\sigma$ $\lesssim$ 15 $ \mu$Jy) radio observations ($\nu$ = 6 GHz; $\lambda$ = 5 cm) of these regions,…

太阳与恒星天体物理 · 物理学 2016-08-06 S. A. Dzib , L. Loinard , S. -N. X. Medina , L. F. Rodríguez , A. J. Mioduszewski , R. M. Torres

Starless dense cores eventually collapse dynamically, which forms protostars inside them, and the physical properties of the cores determine the nature of the forming protostars. We report ALMA observations of dust continuum emission and…

We present results from Very Large Array (VLA) radio continuum observations of twelve intermediate-mass (IM) protostars, as part of the \textit{SOFIA} Massive Star Formation Survey. Using these observations, we studied their morphology,…

We present $4-12$ GHz in-band spectral energy distributions with accompanying 6 GHz and 10 GHz imaging results for a volume-complete sample ($<40$ Mpc) of hard X-ray selected active galactic nuclei (AGNs) observed with the Karl G. Jansky…

The active young protostar DG Tau has an extended jet that has been well studied at radio, optical, and X-ray wavelengths. We report sensitive new VLA full-polarization observations of the core and jet between 5 GHz and 8 GHz. Our high…

太阳与恒星天体物理 · 物理学 2013-03-08 C. Lynch , R. L. Mutel , M. Güdel , T. Ray , S. L. Skinner , P. C. Schneider , K. G. Gayley

We present high-resolution radio observations of a sample of 65 radio sources at low Galactic latitudes. The sources were all observed at 5 GHz with the Very Large Array A-array. MERLIN observations at 5 GHz of the ultracompact HII region…

天体物理学 · 物理学 2009-11-10 D. J. Saikia , P. Thomasson , S. Roy , A. Pedlar , T. W. B. Muxlow

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 results from a study of two luminous IRAS sources thought to be young massive star-forming regions and which have no previously detected radio continuum emission: IRAS 15596-5301 and IRAS 16272-4837. Our study incorporates…

天体物理学 · 物理学 2007-05-23 K. J. Brooks , G. Garay , D. Mardones , R. P. Norris , M. G. Burton

Global VLBI observations at 5 GHz have been performed to study the source morphology in 10 compact steep-spectrum (CSS) sources selected from the Peacock & Wall catalogue with the aim of finding asymmetric structures produced by the…

宇宙学与河外天体物理 · 物理学 2015-06-15 D. Dallacasa , M. Orienti , C. Fanti , R. Fanti , C. Stanghellini