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Related papers: Theoretical ISM pressure and electron density diag…

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We discuss the chemical properties of a sample of UV-selected intermediate-redshift (0 < z < 0.4) galaxies in the context of their physical nature and star formation history. This work represents an extension of our previous studies (Treyer…

Astrophysics · Physics 2009-11-07 T. Contini , M. A. Treyer , M. Sullivan , R. S. Ellis

The redshifted spectral line radiation emitted from both atomic fine-structure and molecular rotational transitions in the interstellar medium (ISM) of high-redshift galaxies can be detected in the centimetre, millimetre and submillimetre…

Astrophysics · Physics 2009-10-31 Andrew W. Blain , D. T. Frayer , J. J. Bock , N. Z. Scoville

(abridged) We present deep spectroscopy of a large sample of low-metallicity emission-line galaxies. The main goal of this study is to derive element abundances in these low-metallicity galaxies. We analyze 121 VLT spectra of HII regions in…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-08 N. G. Guseva , Y. I. Izotov , G. Stasinska , K. J. Fricke , C. Henkel , P. Papaderos

The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3 s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around 1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph} (IRIS) provide a…

Solar and Stellar Astrophysics · Physics 2016-10-19 V. Polito , G. Del Zanna , J. Dudík , H. E. Mason , A. Giunta , K. K. Reeves

We study the direct gas-phase oxygen abundance using the well-detected auroral [OIII]4363 line in the stacked spectra of a sample of local analogs of high-redshift galaxies. These local analogs share the same location as $z\sim2$…

Astrophysics of Galaxies · Physics 2021-10-25 Fuyan Bian , Lisa J. Kewley , Michael A. Dopita

We aim to derive the electron temperature Te in the gas of metal-rich star-forming galaxies, which can be obtained from their ratios of auroral lines [O II]7320,7330 to nebular lines [O II]3727, in order to establish a more robust…

Astrophysics · Physics 2009-11-13 Y. C. Liang , F. Hammer , S. Y. Yin , H. Flores , M. Rodrigues , Yanbin Yang

The relatively red wavelength range (4800-9300{\AA}) of the VLT Multi Unit Spectroscopic Explorer (MUSE) limits which metallicity diagnostics can be used; in particular excluding those requiring the [O ii]{\lambda}{\lambda}3726,29 doublet.…

Astrophysics of Galaxies · Physics 2023-11-08 Bethan Easeman , Patricia Schady , Stijn Wuyts , Robert Yates

ISO has enabled far-infrared spectroscopy of a variety of galaxies. Using the [CII] (158 micron) and [OI](63 micron) lines, we can characterize the physical conditions in the star-forming ISM. These observations also form the basis of our…

Astrophysics · Physics 2007-05-23 Sangeeta Malhotra

In an earlier paper we modeled the far-infrared emission from a star-forming galaxy using the photoionisation code CLOUDY and presented metallicity sensitive diagnostics based on far-infrared fine structure line ratios. Here, we focus on…

We study the ionized gas spectrum of star forming regions in the Holmberg II galaxy using the optical long-slit spectroscopic observations made at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-24 O. V. Egorov , T. A. Lozinskaya , A. V. Moiseev

We have used a combination of stellar population synthesis and photoionization models to develop a set of ionization parameter and abundance diagnostics based only on the use of the strong optical emission lines. These models are applicable…

Astrophysics · Physics 2008-11-26 L. J. Kewley , M. A. Dopita

(Abridged) Aims. We present a homogeneous observational study of electron temperature ($T_{\rm e}$) relations between ionic species: $T_{\rm e}$([N II]), $T_{\rm e}$([O II]), $T_{\rm e}$([O III]), $T_{\rm e}$([S II]), $T_{\rm e}$([S III])…

We describe a new method for determining total gas-phase abundances for the Galactic ISM with minimal ionization uncertainties. For sight lines toward globular clusters containing both UV-bright stars and radio pulsars, one can measure…

Astrophysics · Physics 2009-11-13 J. Christopher Howk , Kenneth R. Sembach , Blair D. Savage

Since its launch, JWST has opened an unprecedented opportunity to characterise the ionised ISM of high-redshift galaxies using well-established rest-frame UV/optical diagnostics from the local Universe. At the same time, these observations…

The global star formation rates (SFR) of galaxies at fixed stellar masses increase with redshift and are known to vary with environment unto z~2. We explore here whether the changes in the star formation rates can also apply to the electron…

Context: It has been proposed that H$_2$ near-infrared lines may be excited by cosmic rays and allow for a determination of the cosmic-ray ionization rate in dense gas. One-dimensional models show that measuring both the H$_2$ gas column…

Astrophysics of Galaxies · Physics 2022-08-24 Brandt A. L. Gaches , Shmuel Bialy , Thomas G. Bisbas , Marco Padovani , Daniel Seifried , Stefanie Walch

One of the most remarkable outcomes from \textit{JWST} has been the exquisite UV-optical spectroscopic data for galaxies in the high-redshift Universe ($z \geq 5$), enabling the use of various nebular emission lines to infer conditions of…

We compare a large sample of galaxies between 0.5<z<2.6 with theoretical predictions for how the optical diagnostic line ratios in galaxy ensembles change as a function of cosmic time. We show that star forming galaxies at high redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Lisa J. Kewley , Christian Maier , Kiyoto Yabe , Kouji Ohta , Masayuki Akiyama , Michael A. Dopita , Tiantian Yuan

The interstellar medium (ISM) consists of highly ionized and neutral atomic, as well as molecular, components. Knowledge of their distribution is important for tracing the structure and lifecycle of the ISM. Here we determine the properties…

Astrophysics of Galaxies · Physics 2016-05-25 W. D. Langer , P. F. Goldsmith , J. L. Pineda

We exploit the unprecedented depth of integral field data from the KMOS Ultra-deep Rotational Velocity Survey (KURVS) to analyse the strong (H$\alpha$) and forbidden ([NII], [SII]) emission line ratios in 22 main-sequence galaxies at…

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