THE SINS SURVEY: BROAD EMISSION LINES IN HIGH-REDSHIFT STAR-FORMING GALAXIES

AbstractTo understand how the nature of the ionizing sources and the leakage of ionizing photons in high-redshift galaxies can be constrained from their emission-line spectra, we compare emission-line models of star-forming galaxies including leakage of ionizing radiation, active galactic nuclei (AGN) and radiative shocks, with observations of galaxies at various redshifts with properties expected to approach those of primeval galaxies.

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Infrared Surveys from Antarctica

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000020415 ◽

1996 ◽

Vol 13 (1) ◽

pp. 7-9 ◽

Cited By ~ 2

Author(s):

Jeremy Bailey

Keyword(s):

Galaxy Evolution ◽

Molecular Hydrogen ◽

High Redshift ◽

Brown Dwarfs ◽

Emission Lines ◽

Star Forming ◽

Hydrogen Emission ◽

Near Ir ◽

Infrared Surveys ◽

Galactic Sources

AbstractThe very low background observed from Antarctica in a window from about 2·25 to 2·45 μm can be exploited as a way of making deep near-IR surveys over wide areas of sky. Imaging surveys using the entire window can cover large areas of sky to limits of around K = 20, and can be used to study galaxy evolution and to search for high-redshift quasars, dust-obscured quasars and brown dwarfs. It is also possible to make spectroscopic surveys in this window. The window includes molecular hydrogen emission and CO absorption in galactic sources, and can also be used to search for emission lines such as Hα in high-redshift star-forming galaxies.

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The WISSH quasars project

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936197 ◽

2020 ◽

Vol 635 ◽

pp. A157 ◽

Cited By ~ 4

Author(s):

A. Travascio ◽

L. Zappacosta ◽

S. Cantalupo ◽

E. Piconcelli ◽

F. Arrigoni Battaia ◽

...

Keyword(s):

Average Velocity ◽

Rest Frame ◽

Velocity Dispersion ◽

High Redshift ◽

Emission Lines ◽

Host Galaxy ◽

Uv Emission ◽

Broad Emission ◽

Highly Sensitive ◽

Integral Field

Context. In recent years, Lyα nebulae have been routinely detected around high redshift, radio-quiet quasars thanks to the advent of the highly sensitive integral field spectrographs. Constraining the physical properties of the Lyα nebulae is crucial for a full understanding of the circum-galactic medium (CGM). The CGM acts both as a repository for intergalactic and galactic baryons as well as a venue of feeding and feedback processes. The most luminous quasars are privileged test-beds to study these processes, given their large ionising fluxes and dense CGM environments in which they are expected to be embedded. Aims. We aim to characterise the rest-frame ultraviolet (UV) emission lines in the CGM around a hyper-luminous, broad emission line, radio-quiet quasar at z ∼ 3.6, which exhibits powerful outflows at both nuclear and host galaxy scales. Methods. We analyse VLT/MUSE observations of the quasar J1538+08 (Lbol = 6 × 1047 erg s−1), and we performed a search for extended UV emission lines to characterise its morphology, emissivity, kinematics, and metal content. Results. We report the discovery of a very luminous (∼2 × 1044 erg s−1), giant Lyα nebula and a likely associated extended (75 kpc) CIV nebula. The Lyα nebula emission exhibits moderate blueshift (∼440 km s−1) compared to the quasar systemic redshift and a large average velocity dispersion (σ¯v ∼ 700 km s−1) across the nebula, while the CIV nebula shows average velocity dispersion of σ¯v ∼ 350 km s−1. The Lyα line profile exhibits a significant asymmetry towards negative velocity values at 20−30 kpc south of the quasar and is well parametrised by the following two Gaussian components: a narrow (σ ∼ 470 km s−1) systemic one plus a broad (σ ∼ 1200 km s−1), blueshifted (∼1500 km s−1) one. Conclusions. Our analysis of the MUSE observation of J1538+08 reveals metal-enriched CGM around this hyper-luminous quasar. Furthermore, our detection of blueshifted emission in the emission profile of the Lyα nebula suggests that powerful nuclear outflows can propagate through the CGM over tens of kiloparsecs.

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Dichotomy of radio loud and radio quiet quasars in four dimensional eigenvector one (4DE1) parameter space

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320003324 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 351-354

Author(s):

Shimeles Terefe ◽

Ascensión del Olmo ◽

Paola Marziani ◽

Mirjana Pović

Keyword(s):

Emission Line ◽

Parameter Space ◽

Signal To Noise Ratio ◽

High Redshift ◽

Emission Lines ◽

Signal To Noise ◽

Broad Emission ◽

Broad Emission Line ◽

Two Populations ◽

Calar Alto

AbstractRecent work has shown that it is possible to systematize quasars (QSOs) spectral diversity in 4DE1 parameter space. The spectra contained in most of the surveys have low signal to noise ratio which fed the impression that all QSOâ€™s are spectroscopically similar. Exploration of 4DE1 parameter space gave rise to the concept of two populations of QSOs that present important spectroscopic differences. We aim to quantify broad emission line differences between radio quiet and radio loud sources by exploiting more complete samples of QSO with spectral coverage in Hβ, MgII and CIV emission lines. We used a high redshift sample (0.35 < z < 1) of strong radio emitter QSOs observations from Calar Alto Observatory in Spain.

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Large reservoirs of turbulent diffuse gas around high-z starburst galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320000836 ◽

2019 ◽

Vol 15 (S352) ◽

pp. 200-204

Author(s):

E. Falgarone ◽

A. Vidal-Garca ◽

B. Godard ◽

M. A. Zwaan ◽

C. Herrera ◽

...

Keyword(s):

Mechanical Energy ◽

Chemical Properties ◽

Starburst Galaxies ◽

Emission Lines ◽

Molecular Gas ◽

Star Forming ◽

Galactic Winds ◽

Broad Emission ◽

The Universe ◽

And Chemical Properties

AbstractStarburst galaxies at z ∼ 2 – 4 are among the most intensely star-forming galaxies in the universe. The way they accrete their gas to form stars at such high rates is still a controversial issue. ALMA has detected the CH+ (J = 1-0) line in emission and/or absorption in all the gravitationally lensed starburst galaxies targeted so far at z ∼ 3. Its unique spectroscopic and chemical properties enable CH+ to highlight the sites of most intense dissipation of mechanical energy. The absorption lines reveal highly turbulent, massive reservoirs of low-density molecular gas. The broad emission lines, arising in myriad UV-irradiated molecular shocks, reveal powerful galactic winds. The CH+ lines therefore probe the fate of prodigious energy releases, due to infall and/or outflows, and primarily stored in turbulence before being radiated by cool molecular gas. The turbulent reservoirs act as mass and energy buffers over the duration of the starburst phase.

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Rest-frame UV and optical emission line diagnostics of ionized gas properties: a test case in a star-forming knot of a lensed galaxy at z ∼ 1.7

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1987 ◽

2019 ◽

Vol 488 (4) ◽

pp. 5862-5886 ◽

Cited By ~ 1

Author(s):

Ayan Acharyya ◽

Lisa J Kewley ◽

Jane R Rigby ◽

Matthew Bayliss ◽

Fuyan Bian ◽

...

Keyword(s):

Rest Frame ◽

High Redshift ◽

Optical Emission ◽

Emission Lines ◽

Log P ◽

Test Case ◽

Single Star ◽

Star Forming ◽

James Webb Space Telescope ◽

Ionization Parameter

Abstract We examine the diagnostic power of rest-frame ultraviolet (UV) nebular emission lines, and compare them to more commonly used rest-frame optical emission lines, using the test case of a single star-forming knot of the bright lensed galaxy RCSGA 032727–132609 at redshift $z$ ∼ 1.7. This galaxy has complete coverage of all the major rest-frame UV and optical emission lines from Magellan/MagE and Keck/NIRSPEC. Using the full suite of diagnostic lines, we infer the physical properties: nebular electron temperature (Te), electron density (ne), oxygen abundance (log (O/H), ionization parameter [log (q), and interstellar medium (ISM) pressure (log (P/k)]. We examine the effectiveness of the different UV, optical, and joint UV–optical spectra in constraining the physical conditions. Using UV lines alone we can reliably estimate log (q), but the same is difficult for log (O/H). UV lines yield a higher (∼1.5 dex) log (P/k) than the optical lines, as the former probes a further inner nebular region than the latter. For this comparison, we extend the existing Bayesian inference code izi, adding to it the capability to infer ISM pressure simultaneously with metallicity and ionization parameter. This work anticipates future rest-frame UV spectral data sets from the James Webb Space Telescope (JWST) at high redshift and from the Extremely Large Telescope (ELT) at moderate redshift.

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Variability of broad emission lines in high-luminosity, high-redshift quasars

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stt1094 ◽

2013 ◽

Vol 434 (2) ◽

pp. 1411-1421 ◽

Cited By ~ 5

Author(s):

Sui Chi Woo ◽

David A. Turnshek ◽

Carles Badenes ◽

Steven Bickerton

Keyword(s):

High Redshift ◽

Emission Lines ◽

High Luminosity ◽

Broad Emission

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The Interpretation of Broad Emission Lines in High-Redshift QSOS

The Astrophysical Journal ◽

10.1086/152966 ◽

1974 ◽

Vol 191 ◽

pp. 291 ◽

Cited By ~ 2

Author(s):

Ronald E. Stoner ◽

Roger Ptak ◽

David Ellis

Keyword(s):

High Redshift ◽

Emission Lines ◽

Broad Emission

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Imaging the molecular interstellar medium in a gravitationally lensed star-forming galaxy at z = 5.7

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935308 ◽

2019 ◽

Vol 628 ◽

pp. A23 ◽

Cited By ~ 9

Author(s):

Yordanka Apostolovski ◽

Manuel Aravena ◽

Timo Anguita ◽

Justin Spilker ◽

Axel Weiß ◽

...

Keyword(s):

Interstellar Medium ◽

Velocity Structure ◽

High Redshift ◽

Emission Lines ◽

Source Plane ◽

Star Forming ◽

Spatially Resolved ◽

Disk Rotation ◽

Imaging Results ◽

Line Imaging

Aims. We present and study spatially resolved imaging obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of multiple 12CO(J = 6 − 5, 8−7, and 9−8) and two H2O(202−111 and 211−202) emission lines and cold dust continuum toward the gravitationally lensed dusty star-forming galaxy SPT 0346-52 at z = 5.656. Methods. Using a visibility-domain source-plane reconstruction we probe the structure and dynamics of the different components of the interstellar medium (ISM) in this galaxy down to scales of 1 kpc in the source plane. Results. Measurements of the intrinsic sizes of the different CO emission lines indicate that the higher J transitions trace more compact regions in the galaxy. Similarly, we find smaller dust continuum intrinsic sizes with decreasing wavelength, based on observations at rest frame 130, 300, and 450 μm. The source shows significant velocity structure, and clear asymmetry where an elongated structure is observed in the source plane with significant variations in their reconstructed sizes. This could be attributed to a compact merger or turbulent disk rotation. The differences in velocity structure through the different line tracers, however, hint at the former scenario in agreement with previous [CII] line imaging results. Measurements of the CO line ratios and magnifications yield significant variations as a function of velocity, suggesting that modeling of the ISM using integrated values could be misinterpreted. Modeling of the ISM in SPT 0346-52 based on delensed fluxes indicates a highly dense and warm medium, qualitatively similar to that observed in high-redshift quasar hosts.

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A synergy of the velocity gradients technique and the probability density functions for identifying gravitational collapse in self-absorbing media

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab087 ◽

2021 ◽

Vol 502 (2) ◽

pp. 1768-1784

Author(s):

Yue Hu ◽

A Lazarian

Keyword(s):

Magnetic Fields ◽

Probability Density ◽

Column Density ◽

Mass Density ◽

Probability Density Functions ◽

Emission Lines ◽

Density Functions ◽

Star Forming ◽

Velocity Gradients ◽

Self Gravity

ABSTRACT The velocity gradients technique (VGT) and the probability density functions (PDFs) of mass density are tools to study turbulence, magnetic fields, and self-gravity in molecular clouds. However, self-absorption can significantly make the observed intensity different from the column density structures. In this work, we study the effects of self-absorption on the VGT and the intensity PDFs utilizing three synthetic emission lines of CO isotopologues 12CO (1–0), 13CO (1–0), and C18O (1–0). We confirm that the performance of VGT is insensitive to the radiative transfer effect. We numerically show the possibility of constructing 3D magnetic fields tomography through VGT. We find that the intensity PDFs change their shape from the pure lognormal to a distribution that exhibits a power-law tail depending on the optical depth for supersonic turbulence. We conclude the change of CO isotopologues’ intensity PDFs can be independent of self-gravity, which makes the intensity PDFs less reliable in identifying gravitational collapsing regions. We compute the intensity PDFs for a star-forming region NGC 1333 and find the change of intensity PDFs in observation agrees with our numerical results. The synergy of VGT and the column density PDFs confirms that the self-gravitating gas occupies a large volume in NGC 1333.

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