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Accretion flows onto massive stars must transfer mass so quickly that they are themselves gravitationally unstable, forming dense clumps and filaments. These density perturbations interact with young massive stars, emitting ionizing…

Astrophysics of Galaxies · Physics 2013-12-31 C. G. De Pree , T. Peters , M. -M. Mac Low , D. J. Wilner , W. M. Goss , R. Galván-Madrid , E. R. Keto , R. S. Klessen , A. Monsrud

We present methods and results from "21-cm Spectral Line Observations of Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With the upgraded…

We report systematic mapping observations of the NH$_{3}$ (1,1) and (2,2) inversion lines towards 62 high-mass star-forming regions using VLA in its D and DnC array configurations. The VLA images cover a spatial dynamic range from 40$"$ to…

Astrophysics of Galaxies · Physics 2015-06-19 Xing Lu , Qizhou Zhang , Hauyu Baobab Liu , Junzhi Wang , Qiusheng Gu

We present the results of an outflow and infall survey towards a distance limited sample of 31 massive star forming regions drawn from the RMS survey. The presence of young, active outflows is identified from SiO (8-7) emission and the…

Astrophysics of Galaxies · Physics 2018-04-04 Nichol Cunningham , Stuart Lumsden , Toby Moore , Luke Maud , Ignacio. Mendigutia

We present the first results of an ongoing campaign using the STIS spectrograph on-board the Hubble Space Telescope (HST) whose primary goal is the study of near ultraviolet (UV) spectra of local Type Ia supernovae (SNe Ia). Using events…

Gas infall motions play a crucial role in high-mass star formation and are characterized by observable signatures in the form of blue-shifted asymmetric spectral line profiles ("blue profiles"). However, the connection between blue profiles…

Astrophysics of Galaxies · Physics 2023-09-27 Fengwei Xu , Ke Wang , Yuxin He , Jingwen Wu , Lei Zhu , Diego Mardones

Absorption lines at high redshift in front of quasars are rare in the mm domain. Only five associated and five intervening systems have been reported in the literature. These bring very useful information complementary to emission lines,…

Astrophysics of Galaxies · Physics 2023-12-19 Francoise Combes , Neeraj Gupta

(Abridged) Aims. In the present part of our survey we search for ammonia emitters in the Aquila rift complex which trace the densest regions of molecular clouds. Methods. From a CO survey carried out with the Delingha 14-m telescope we…

Astrophysics of Galaxies · Physics 2015-06-15 S. A. Levshakov , C. Henkel , D. Reimers , M. Wang , R. Mao , H. Wang , Y. Xu

We present near-infrared [Fe II] images of four Class 0/I jets (HH 1/2, HH 34, HH 111, HH 46/47) observed with the Hubble Space Telescope Wide Field Camera 3. The unprecedented angular resolution allows us to measure proper motions, jet…

We have carried out a survey toward the central regions of 85 starless cores in HCN J = 1-0 to study inward motions in the cores. Sixty-four cores were detected with HCN lines. The infall asymmetry in the HCN spectra is found to be more…

Astrophysics · Physics 2009-06-23 Jungjoo Sohn , Chang Won Lee , Yong-Sun Park , Hyung Mok Lee , Philip C. Myers , Youngung Lee

Atomic ionised regions with strong continuum emission are often associated with regions of high-mass star formation and low-frequency (<2GHz) observations of these regions are needed to help build star formation models. The region toward…

Astrophysics of Galaxies · Physics 2021-12-08 Chenoa D. Tremblay , Tyler L. Bourke , James A. Green , John M. Dickey , O. Ivy Wong , Tim J. Galvin

Combining the relative vicinity of the Local Group spiral galaxy M33 with the Spitzer images, we investigate the properties of infrared (IR) emission sites and assess the reliability of the IR emission as a star formation tracer. The mid-…

Astrophysics · Physics 2009-11-13 S. Verley , L. K. Hunt , E. Corbelli , C. Giovanardi

We report the discovery of a Type Ia supernova (SNIa) at redshift z=1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble…

Although type Ia supernovae (SNe Ia) are very useful in many astrophysical fields, their exact nature is still unclear, e.g. the progenitor and explosion models. The high-velocity features (HVFs) in optical spectra of SNe Ia could provide…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Xiangcun Meng

The third Gaia data release includes 33.8 million radial velocity measurements, extending to a magnitude of G_RVS = 14. To reach this magnitude limit, spectra were processed down to a signal-to-noise ratio (S/N) of 2. In this very low S/N…

We present data from mid-infrared Keck Telescope imaging of 18 radio-selected ultra-compact HII region candidates at diffraction-limited resolution. The goal of these observations is to determine the sizes, luminosities, and morphologies of…

Astrophysics · Physics 2008-11-26 Uriel Giveon , Matthew J. Richter , Robert H. Becker , Richard L. White

The discovery of a previously unknown 21cm HI line source identified as an ultra-compact high velocity cloud in the ALFALFA survey is reported. The HI detection is barely resolved by the Arecibo 305m telescope ~4' beam and has a narrow HI…

We have discovered 21 new Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to trace the history of cosmic expansion over the last 10 billion years. These objects, which include 13 spectroscopically…

We present Submillimeter Array (SMA) observations of the HCN\,(3--2) and HCO$^+$\,(3--2) molecular lines toward the W3(H$_2$O) and W3(OH) star-forming complexes. Infall and outflow motions in the W3(H$_2$O) have been characterized by…

Solar and Stellar Astrophysics · Physics 2016-01-27 Sheng-Li Qin , Peter Schilke , Jingwen Wu , Tie Liu , Yuefang Wu , Álvaro Sánchez-Monge , Ying Liu