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In the next few years, intensity-mapping surveys that target lines such as CO, Ly$\alpha$, and CII stand to provide powerful probes of high-redshift astrophysics. However, these line emissions are highly non-Gaussian, and so the typical…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-01 Patrick C. Breysse , Ely D. Kovetz , Peter S. Behroozi , Liang Dai , Marc Kamionkowski

Radiative transfer effects due to overlapping X-ray lines in a high-temperature, optically-thick, highly-ionized medium are investigated. One particular example, where the O VIII Ly-alpha doublet coincide in frequency with the N VII Ly-zeta…

Astrophysics · Physics 2009-11-07 Masao Sako

We analyse synthetic $^{12}$CO, $^{13}$CO, and [CII] emission maps of simulated molecular clouds of the SILCC-Zoom project, which include an on-the-fly evolution of H$_2$, CO, and C$^+$. We use simulations of hydrodynamical and…

Astrophysics of Galaxies · Physics 2022-07-12 S. Ebagezio , D. Seifried , S. Walch , P. C. Nürnberger , T. E. Rathjen , T. Naab

A comprehensive model atom was constructed for C I using the most up-to-date atomic data. We evaluated non-local thermodynamical equilibrium (NLTE) line formation for neutral carbon in classical 1D models representing atmospheres of…

Solar and Stellar Astrophysics · Physics 2015-09-09 S. A. Alexeeva , L. I. Mashonkina

Ions (e.g., H$_3^+$, H$_2$O$^+$) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of CRIR in low-to-intermediate density gas environments are rare, especially when…

Astrophysics of Galaxies · Physics 2023-01-19 Gan Luo , Zhi-Yu Zhang , Thomas G. Bisbas , Di Li , Ningyu Tang , Junzhi Wang , Ping Zhou , Pei Zuo , Nannan Yue , Jing Zhou , Lingrui Lin

We selected 90 massive star-forming clumps with strong N2H+, HCO+, HCN, and HNC emission from the Millimetre Astronomy Legacy Team 90 GHz survey. We obtained Herschel data for all 90 sources and NRAO VLA Sky Survey data for 51 of them. We…

Astrophysics of Galaxies · Physics 2019-07-25 Mingyue Li , Jianjun Zhou , Jarken Esimbek , Donghui Quan , Yuxin He , Qiang Li , Chunhua Zhu

We present the study of a Lyman limit system (LLS) at $z_{\rm abs}$ = 1.5441 towards quasar J134122.50+185213.9 observed with VLT X-shooter. This is a very peculiar system with strong C I absorption seen associated with a neutral hydrogen…

Infrared stellar photometry from 2MASS and spectral line imaging observations of 12CO and 13CO J = 1-0 line emission from the FCRAO 14m telescope are analysed to assess the variation of the CO abundance with physical conditions throughout…

Astrophysics of Galaxies · Physics 2015-06-15 F. Ripple , M. H. Heyer , R. Gutermuth , R. L. Snell , C. M. Brunt

We report results for a complete sample of ten luminous radio-quiet quasars with large C IV equivalent widths (EW > 150 A). For 8/10 we performed Chandra snapshot observations. We find that, in addition to the enhanced C IV line EW, their…

Astrophysics of Galaxies · Physics 2022-08-03 Shuqi Fu , W. N. Brandt , Fan Zou , Ari Laor , Gordon P. Garmire , Qingling Ni , John D. Timlin , Yongquan Xue

We study the ultraviolet (UV) emission-line ratios of a sample of 145 type II quasars (QSO2s) from Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey, and compare against a grid of active galactic nucleus (AGN)…

Astrophysics of Galaxies · Physics 2020-07-28 M. Silva , A. Humphrey , P. Lagos , S. G. Morais

We present a millimetre molecular line survey of seven high mass loss rate carbon stars in both the northern and southern skies. A total of 196 emission lines (47 transitions) from 24 molecular species were detected. The observed CO…

Astrophysics · Physics 2009-11-07 P. M. Woods , F. L. Schoeier , L. -A. Nyman , H. Olofsson

Cosmic rays (CRs) have strong influences on the chemistry of dense molecular clouds (MCs). To study the detailed chemistry induced by CRs, we conducted a Yebes W band line survey towards an unshocked MC (which we named as 3C391:NML)…

Astrophysics of Galaxies · Physics 2024-08-28 Tian-Yu Tu , Prathap Rayalacheruvu , Liton Majumdar , Yang Chen , Ping Zhou , Miguel Santander-García

We present a new method to derive oxygen and carbon abundances using the ultraviolet (UV) lines emitted by the gas-phase ionised by massive stars. The method is based on the comparison of the nebular emission-line ratios with those…

Astrophysics of Galaxies · Physics 2017-03-13 Enrique Pérez-Montero , Ricardo Amorín

Context: There is a lively debate about the solar oxygen abundance and the role of 3D models in its recent downward revision. The models have been tested using high resolution solar atlases. Further testing can be done using centre-to-limb…

Solar and Stellar Astrophysics · Physics 2015-05-14 Tiago M. D. Pereira , Martin Asplund , Dan Kiselman

Observations of some starburst-driven galactic superwinds suggest that strong radiative cooling could play a key role in the nature of feedback and the formation of stars and molecular gas in star-forming galaxies. These catastrophically…

Astrophysics of Galaxies · Physics 2022-09-30 A. Danehkar , M. S. Oey , W. J. Gray

I give an overview of the rich phenomenology of dwarf nova oscillations (DNOs) and Quasi-periodic Oscillations (QPOs) observed in cataclysmic variable stars (CVs). The favoured interpretation of these rapid brightness modulations (3 - >1000…

Astrophysics · Physics 2009-11-10 Brian Warner

This paper provides a general reference for deriving the ionizations and metal abundances for absorption-line clouds in photoionization equilibrium with a QSO spectrum. The results include a quantitative assessment of the theoretical…

Astrophysics · Physics 2009-10-30 Fred Hamann

The abundance of cold molecular gas plays a crucial role in models of galaxy evolution. While deep spectroscopic surveys of CO emission lines have been a primary tool for measuring this abundance, the difficulty of these observations has…

Astrophysics of Galaxies · Physics 2022-03-30 Ryan P. Keenan , Garrett K. Keating , Daniel P. Marrone

The solar photospheric carbon abundance has been determined from [C I], C I, CH vibration-rotation, CH A-X electronic and C2 Swan electronic lines by means of a time-dependent, 3D, hydrodynamical model of the solar atmosphere. Departures…

Astrophysics · Physics 2009-11-10 M. Asplund , N. Grevesse , A. J. Sauval , C. Allende Prieto , R. Blomme

Detections of molecular lines, mainly from H2$ and CO, reveal molecular material in planetary nebulae. Observations of a variety of molecules suggest that the molecular composition in these objects differs from that found in interstellar…

Astrophysics of Galaxies · Physics 2012-06-28 Rafael K. Kimura , Ruth Gruenwald , Isabel Aleman