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Related papers: Hydrogen Masers. II: MWC349

200 papers

Rovibronic molecular hydrogen (H$_2$) transitions at redshift $z_{\rm abs} \simeq 2.659$ towards the background quasar B0642$-$5038 are examined for a possible cosmological variation in the proton-to-electron mass ratio, $\mu$. We utilise…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Julija Bagdonaite , Wim Ubachs , Michael T. Murphy , Jonathan B. Whitmore

We study strong field ionization of molecular hydrogen in highly intense co-rotating two-color (CoRTC) laser fields. The measured electron momentum distributions show alternating half-rings (AHR) that are characteristic for sub-cycle…

We present a simultaneous single-dish survey of 22 GHz water maser and 44 GHz and 95 GHz class I methanol masers toward 77 6.7 GHz class II methanol maser sources, which were selected from the Arecibo methanol maser Galactic plane survey…

Solar and Stellar Astrophysics · Physics 2015-11-18 Hyunwoo Kang , Kee-Tae Kim , Do-Young Byun , Seokho Lee , Yong-Sun Park

We report the first detection of radio recombination lines (RRLs) of ions heavier than helium. In a highly sensitive multi-band (12--50 GHz) line survey toward Orion KL with the TianMa 65-m Radio Telescope (TMRT), we successfully detected…

A renewed attempt to detect radio recombination lines from external galaxies has resulted in the measurement of lines from several bright starburst galaxies. The lines are produced by hydrogen ionized by young, high-mass stars and are…

Astrophysics · Physics 2009-11-10 A. L. Roy , W. M. Goss , Niruj R. Mohan , T. Oosterloo , K. R. Anantharamaiah

For the first time in an extragalactic source, we detect linearly polarized water maser emission associated with the molecular accretion disk of NGC 1068. The position angles of the electric polarization vectors are perpendicular to the…

The kinetics of hydrogen diffusion in C15 cubic and C14 hexagonal TiCr$_2$H$_x$ (0 < $x$ <= 4) Laves-phase hydrogen storage alloys is investigated with density functional theory (DFT) and machine learning interatomic potentials (MLIPs).…

Materials Science · Physics 2026-02-26 Pranav Kumar , Fritz Körmann , Kaveh Edalati , Blazej Grabowski , Yuji Ikeda

The power mechanism and accretion geometry for low-power FR1 radio galaxies is poorly understood in comparison to Seyfert galaxies and QSOs. In this paper we use the diagnostic power of the Lya recombination line observed using the Cosmic…

Astrophysics of Galaxies · Physics 2016-12-07 Charles W. Danforth , John T. Stocke , Kevin France , Mitchell C. Begelman , Eric Perlman

We present ALMA and ACA [CI]$^{3}P_{1}-^{3}P_{0}$ ([CI](1-0)) observations of NGC6240, which we combine with ALMA CO(2-1) and IRAM PdBI CO(1-0) data to study the physical properties of the massive molecular (H$_2$) outflow. We discover that…

We investigate the prospects of blind and targeted searches in the radio domain (10 MHz to 1 THz) for high-n hydrogen recombination lines from the first generation of galaxies, at z < 10. The expected optically thin spontaneous alpha-line…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Evan Rule , Abraham Loeb , Vladimir Strelnitski

A handful of well-studied Weak-Line Radio Galaxies (WLRGs) have been traditionally classified as Low Ionization Nuclear Emission-line Regions (LINERs), suggesting that these two groups of AGNs might be related. In this paper, we present new…

Astrophysics · Physics 2009-11-07 Karen T. Lewis , Michael Eracleous , Rita M. Sambruna

We have discovered a third quasar absorption system which is consistent with a low deuterium to hydrogen abundance ratio, D/H = 3.4 times 10^-5. The z ~ 2.8 partial Lyman limit system towards QSO 0130-4021 provides the strongest evidence to…

Astrophysics · Physics 2009-10-31 David Kirkman , David Tytler , Scott Burles , Dan Lubin , John M. O'Meara

We have used the Australia Telescope Compact Array (ATCA) to search for emission from the $4_{-1} \rightarrow 3_{0}E$ transition of methanol (36.2 GHz) towards the center of the nearby starburst galaxy NGC253. Two regions of emission were…

Astrophysics of Galaxies · Physics 2015-06-22 Simon Ellingsen , Xi Chen , Hai-Hua Qiao , Willem Baan , Tao An , Juan Li , Shari Breen

We present results of deep echelle spectrophotometry of eight Galactic HII regions located at Galactocentric distances between 6.3 and 10.4 kpc. The data have been taken with the Very Large Telescope (VLT) Ultraviolet Echelle Spectrograph…

Astrophysics · Physics 2009-11-10 C. Esteban , J. Garcia-Rojas , M. Peimbert , A. Peimbert , M. T. Ruiz , M. Rodriguez , L. Carigi

We investigate two chemical abundance calibrations for the narrow-line-region (NLR) of active galaxies in terms of three easily observable optical emission-line ratios, namely, [OIII]$\lambda\lambda$4959,5007/H$\beta$,…

We report on detailed Monte Carlo inversion analysis of the Lyman limit system observed at z = 2.917 in the VLT/UVES spectrum of the quasar HE 0940-1050. Metal absorption lines of carbon and silicon in three ionization stages and numerous…

Astrophysics · Physics 2009-11-07 S. A. Levshakov , I. I. Agafonova , M. Centurion , P. Molaro

We investigate the clustering and halo properties of $\sim 5000$ Ly$\alpha$-selected emission line galaxies (LAEs) from the Slicing COSMOS 4K (SC4K) and from archival NB497 imaging of SA22 split in 15 discrete redshift slices between $z…

From UV spectra of the bright quasar PHL 1811 recorded by FUSE and the E140M configuration on STIS, we have determined the abundances of various atomic species in a Lyman limit system at z = 0.0809 with log N(H I) = 17.98. Considerably more…

Astrophysics · Physics 2008-11-26 Edward B. Jenkins , David V. Bowen , Todd M. Tripp , Kenneth R. Sembach

Boundary helical Luttinger liquid (HLL) with broken bulk time-reversal symmetry belongs to a unique topological class which may occur in antiferromagnets (AFM). Here, we search for signatures of HLL on the edge of a recently discovered…

We determine abundances from the absorption spectrum of the magnetic Herbig Ae star HD 190073 (V1295 Aql). The observations are primarily from HARPS spectra obtained at a single epoch. We accept arguments that the presence of numerous…

Solar and Stellar Astrophysics · Physics 2015-06-03 C. R. Cowley , S. Hubrig