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相关论文: Hydrogen Masers. II: MWC349

200 篇论文

We present a systematic study of deuterated molecular hydrogen (HD) at high redshift, detected in absorption in the spectra of quasars. We present four new identifications of HD lines associated with known $\rm H_2$-bearing Damped…

星系天体物理 · 物理学 2021-06-30 D. N. Kosenko , S. A. Balashev , P. Noterdaeme , J. -K. Krogager , R. Srianand , C. Ledoux

Cosmological constraints from the cosmic microwave background (CMB) anisotropies rely on accurate theoretical calculations of the cosmic recombination history. Recent work has emphasized the importance of radiative transfer calculations due…

宇宙学与河外天体物理 · 物理学 2014-11-18 Christopher M. Hirata , John Forbes

Hydrogen Lyman-$\alpha$ (Ly$\alpha$) emission has been one of the major observational probes for the high redshift universe, since the first discoveries of high-$z$ Ly$\alpha$ emitting galaxies in the late 1990s. Due to the strong…

星系天体物理 · 物理学 2020-12-16 Masami Ouchi , Yoshiaki Ono , Takatoshi Shibuya

Here we report on observations of powerful hydroxyl (OH) line emissions that trace the obscuring material within the circumnuclear environment of the galaxy Markarian 231. The hydroxyl (mega)-maser emission shows the characteristics of a…

天体物理学 · 物理学 2007-05-23 Hans-Rainer Kl"ockner , Willem A. Baan , Michael A. Garrett

Of 104 AGN known to exhibit H$_2$O maser emission, X-ray data that enable estimation of column densities, or lower limits, are available for 42. Contributing to this, we report analysis of new and archival X-ray data for 8 galaxies and…

天体物理学 · 物理学 2009-11-13 Lincoln J. Greenhill , Avanti Tilak , Grzegorz Madejski

The Australia Telescope Compact Array (ATCA) has been used to image class I methanol masers at 9.9, 25 (a series from J=2 to J=9), 84, 95 and 104 GHz located in the vicinity of IRAS 16547-4247 (G343.12-0.06), a luminous young stellar object…

天体物理学 · 物理学 2008-11-26 M. A. Voronkov , K. J. Brooks , A. M. Sobolev , S. P. Ellingsen , A. B. Ostrovskii , J. L. Caswell

The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1…

Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared (HIFI), we have performed mapping observations of the 620.701 GHz 5(32)-4(41) transition of ortho-H2O within a roughly 1.5 x 1.5 arcmin region encompassing…

星系天体物理 · 物理学 2015-06-15 David A. Neufeld , Yuanwei Wu , Alex Kraus , Karl M. Menten , Volker Tolls , Gary J. Melnick , Zsofia Nagy

We have selected the positions of 54 6.7GHz methanol masers from the Methanol Multibeam Survey catalogue, covering a range of longitudes between $20^{\circ}$ and $34^{\circ}$ of the Galactic Plane. These positions were mapped in the J=3-2…

Observations of millimeter wavelength radio recombination lines (mm-RRLs) are used to search for HII regions in an unbiased way that is complementary to many of the more traditional methods previously used. We carried out targeted mm-RRL…

星系天体物理 · 物理学 2017-06-07 W. -J. Kim , F. Wyrowski , J. S. Urquhart , K. M. Menten , T. Csengeri

We report the detection of a rich spectrum of more than one hundred optical emission lines of vibrationally hot molecular hydrogen (H2) from the photodissociation region (PDR) around the mini-starburst cluster NGC 346 in the Small…

星系天体物理 · 物理学 2024-02-15 William J. Henney , Mabel Valerdi

Spectra, taken with the heterodyne instrument, HIFI, aboard the Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part of the guaranteed time key program HIFISTARS are presented. The aim of this program is…

We present JWST NIRSpec and MIRI MRS observations of the central kiloparsec of M58 (NGC 4579), a nearby LINER galaxy hosting a low-luminosity AGN (LLAGN; $L_\mathrm{bol} \sim 10^{42}$ erg s$^{-1}$) with a low-power jet. These data provide…

A study of the variability of the broad emission-line parameters of 3C390.3, an active galaxy with the double-peaked emission-line profiles, is presented. We give a detail analysis of variation in the broad Ha and Hb profiles, the ratios,…

We present the results of the further investigation of the Class II methanol maser emission in the $14_1 - 14_0$ A$^{-+}$ transition at 349.1 GHz discovered in 2016 in the remarkable core S255IR-SMA1, harboring a $\sim$20 M$_\odot$…

星系天体物理 · 物理学 2025-08-01 I. I. Zinchenko , S. V. Salii , A. M. Sobolev , I. A. Zaichikova , S. -Y. Liu , Y. -N. Su

We have used the Australia Telescope Compact Array (ATCA) to make new observations of the 36.2-GHz ($4_{-1}\rightarrow3_0$E) methanol transition toward NGC 4945 and NGC 253. These observations have revealed the presence of new maser…

星系天体物理 · 物理学 2021-10-20 Tiege McCarthy , Simon Ellingsen , Shari Breen , Maxim Voronkov , Xi Chen , Hai-Hua Qiao

We present observations of the 36- (4_-1 -> 3_0E) and 84-GHz (5_-1 -> 4_0 E) class I methanol maser transitions towards a sample of 94 known class I sites. These observations resulted in 93 and 92 detections in the 84- and 36-GHz…

星系天体物理 · 物理学 2019-01-30 Shari Breen , Yanett Contreras , Joanne Dawson , Simon Ellingsen , Maxim Voronkov , Tiege McCarthy

We investigate the effect of a global change in the ionizing continuum level on the behavior of the strong optical broad emission-lines seen in spectra of the nuclear emission-line regions of active galactic nuclei (AGN), including the…

天体物理学 · 物理学 2009-11-10 Kirk T. Korista , Michael R. Goad

I review the basic properties of low-ionization nuclear emission-line regions (LINERs), as well as the main ionization mechanisms thus far proposed for them. There is substantial heterogeneity among LINERs, especially those with extended…

天体物理学 · 物理学 2007-05-23 Alexei V. Filippenko

We present the results of studies of a new class of 6.7 GHz methanol maser sources with a ring-like emission structure discovered recently with the EVN. We have used the VLA to search for water masers at 22 GHz and radio continuum at 8.4…

星系天体物理 · 物理学 2015-03-18 A. Bartkiewicz , M. Szymczak , H. J. van Langevelde , J. M. De Buizer , Y. Pihlström