Centimeter Searches for Molecular Line Emission from High‐Redshift Galaxies

2002 ◽  
Vol 569 (2) ◽  
pp. 605-610 ◽  
Author(s):  
C. L. Carilli ◽  
A. W. Blain
Keyword(s):  
High Redshift ◽  
Line Emission ◽  
Molecular Line ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Observations of Molecules in High Redshift Galaxies

2011 ◽  
Vol 7 (S280) ◽  
pp. 325-338
Author(s):  
Kirsten Kraiberg Knudsen
Keyword(s):  
Small Molecules ◽  
High Redshift ◽  
Molecular Gas ◽  
Molecular Line ◽  
High Redshift Galaxies ◽  
The Past ◽  
Tremendous Progress ◽  
Submillimeter Galaxies ◽  
Redshift Galaxies

AbstractI present an overview of the molecular gas observations in high redshift galaxies. This field has seen tremendous progress in the past few years, with an increased number of detections of other molecules than CO. The molecular line observations are done towards different classes of massive starbursts, including submillimeter galaxies, quasars, and massive gas-rich disks. I will highlight results of detections of HCN, HCO+, and other small molecules, as well as the Spitzer detections of PAHs. Additionally, I will discuss about the excitation of CO and other species in the high-z galaxies and put this in the context of new telescopes such as ALMA.

Infrared line emission from high-redshift galaxies. 1: Calculations

1995 ◽  
Vol 442 ◽  
pp. 569 ◽  
Author(s):  
Filippo Mannucci ◽  
Steven V. W. Beckwith
Keyword(s):  
High Redshift ◽  
Line Emission ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Strongly time-variable ultraviolet metal-line emission from the circum-galactic medium of high-redshift galaxies

2016 ◽  
Vol 463 (1) ◽  
pp. 120-133 ◽  
Author(s):  
Niharika Sravan ◽  
Claude-André Faucher-Giguère ◽  
Freeke van de Voort ◽  
Dušan Kereš ◽  
Alexander L. Muratov ◽  
...  
Keyword(s):  
High Redshift ◽  
Line Emission ◽  
Time Variable ◽  
Metal Line ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Far-infrared line emission from high-redshift galaxies

2013 ◽  
Vol 433 (2) ◽  
pp. 1567-1572 ◽  
Author(s):  
Livia Vallini ◽  
Simona Gallerani ◽  
Andrea Ferrara ◽  
Sunghye Baek
Keyword(s):  
High Redshift ◽  
Line Emission ◽  
Far Infrared ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Dust and gas content of high-redshift galaxies hosting obscured AGN in the Chandra Deep Field-South

2020 ◽  
Vol 636 ◽  
pp. A37 ◽  
Author(s):  
Q. D’Amato ◽  
R. Gilli ◽  
C. Vignali ◽  
M. Massardi ◽  
F. Pozzi ◽  
...  
Keyword(s):  
Flux Density ◽  
High Redshift ◽  
Line Emission ◽  
Major Axis ◽  
Gas Content ◽  
Molecular Gas ◽  
High Redshift Galaxies ◽  
X Ray ◽  
The Continuum ◽  
Redshift Galaxies

Context. Obscured active galactic nuclei (AGN) represent a significant fraction of the entire AGN population, especially at high redshift (∼70% at z = 3 − 5). They are often characterized by the presence of large gas and dust reservoirs that are thought to sustain and possibly obscure vigorous star formation processes that make these objects shine at FIR and submillimeter wavelengths. Studying the physical properties of obscured AGN and their host galaxies is crucial to shedding light on the early stages of a massive system lifetime. Aims. We aim to investigate the contribution of the interstellar medium (ISM) to the obscuration of quasars in a sample of distant highly star forming galaxies and to unveil their morphological and kinematics properties. Methods. We exploit Atacama Large Millimeter/submillimeter Array Cycle 4 observations of the continuum (∼2.1 mm) and high-J CO emission of a sample of six X-ray selected, FIR detected galaxies hosting an obscured AGN at zspec >  2.5 in the 7 Ms Chandra Deep Field-South. We measured the masses and sizes of the dust and molecular gas by fitting the images, visibilities, and spectra, and we derived the gas density and column density on the basis of a uniform sphere geometry. Finally, we compared the measured column densities with those derived from the Chandra X-ray spectra. Results. We detected both the continuum and line emission for three sources for which we measured both the flux density and size. For the undetected sources, we derived an upper limit on the flux density from the root mean square of the images. We found that the detected galaxies are rich in gas and dust (molecular gas mass in the range < 0.5–2.7 × 1010 M⊙ for αCO = 0.8 and up to ∼2 × 1011 M⊙ for αCO = 6.5, and dust mass < 0.9–4.9 × 108 M⊙) and generally compact (gas major axis 2.1–3.0 kpc, dust major axis 1.4–2.7 kpc). The column densities associated with the ISM are on the order of 1023 − 24 cm−2, which is comparable with those derived from the X-ray spectra. For the detected sources we also derived dynamical masses in the range 0.8–3.7 × 1010 M⊙. Conclusions. We conclude that the ISM of high redshift galaxies can substantially contribute to nuclear obscuration up to the Compton-thick (> 1024 cm−2) regime. In addition, we found that all the detected sources show a velocity gradient reminding one rotating system, even though two of them show peculiar features in their morphology that can be associated with a chaotic, possibly merging, structure.

scholarly journals The [CII] 158 μm line emission in high-redshift galaxies

2018 ◽  
Vol 609 ◽  
pp. A130 ◽  
Author(s):  
G. Lagache ◽  
M. Cousin ◽  
M. Chatzikos
Keyword(s):  
Galaxy Evolution ◽  
High Redshift ◽  
Formation Rate ◽  
Line Emission ◽  
Interstellar Gas ◽  
Structure Transition ◽  
High Redshift Galaxies ◽  
Star Forming ◽  
Crucial Component ◽  
Redshift Galaxies

Gas is a crucial component of galaxies, providing the fuel to form stars, and it is impossible to understand the evolution of galaxies without knowing their gas properties. The [CII] fine structure transition at 158 μm is the dominant cooling line of cool interstellar gas, and is the brightest of emission lines from star forming galaxies from FIR through metre wavelengths, almost unaffected by attenuation. With the advent of ALMA and NOEMA, capable of detecting [CII]-line emission in high-redshift galaxies, there has been a growing interest in using the [CII] line as a probe of the physical conditions of the gas in galaxies, and as a star formation rate (SFR) indicator at z ≥ 4. In this paper, we have used a semi-analytical model of galaxy evolution (G.A.S.) combined with the photoionisation code CLOUDY to predict the [CII] luminosity of a large number of galaxies (25 000 at z ≃ 5) at 4 ≤ z ≤ 8. We assumed that the [CII]-line emission originates from photo-dominated regions. At such high redshift, the CMB represents a strong background and we discuss its effects on the luminosity of the [CII] line. We studied the L[CII ]–SFR and L[ CII ]–Zg relations and show that they do not strongly evolve with redshift from z = 4 and to z = 8. Galaxies with higher [CII] luminosities tend to have higher metallicities and higher SFRs but the correlations are very broad, with a scatter of about 0.5 and 0.8 dex for L[ CII ]–SFR and L[ CII ]–Zg, respectively. Our model reproduces the L[ CII ]–SFR relations observed in high-redshift star-forming galaxies, with [CII] luminosities lower than expected from local L[ CII ]–SFR relations. Accordingly, the local observed L[ CII ]–SFR relation does not apply at high-z (z ≳ 5), even when CMB effects are ignored. Our model naturally produces the [CII] deficit (i.e. the decrease of L[ CII ]/LIR with LIR), which appears to be strongly correlated with the intensity of the radiation field in our simulated galaxies. We then predict the [CII] luminosity function, and show that it has a power law form in the range of L[ CII] probed by the model (1 × 107–2 × 109 L⊙ at z = 6) with a slope α = −1. The slope is not evolving from z = 4 to z = 8 but the number density of [CII]-emitters decreases by a factor of 20×. We discuss our predictions in the context of current observational estimates on both the differential and cumulative luminosity functions.

scholarly journals TRACING THE EVOLUTION OF HIGH-REDSHIFT GALAXIES USING STELLAR ABUNDANCES

2016 ◽  
Vol 820 (1) ◽  
pp. 71 ◽  
Author(s):  
Brian D. Crosby ◽  
Brian W. O’Shea ◽  
Timothy C. Beers ◽  
Jason Tumlinson
Keyword(s):  
High Redshift ◽  
Stellar Abundances ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Self-consistent proto-globular cluster formation in cosmological simulations of high-redshift galaxies

2020 ◽  
Vol 493 (3) ◽  
pp. 4315-4332 ◽  
Author(s):  
Xiangcheng Ma ◽  
Michael Y Grudić ◽  
Eliot Quataert ◽  
Philip F Hopkins ◽  
Claude-André Faucher-Giguère ◽  
...  
Keyword(s):  
High Pressure ◽  
Star Formation ◽  
High Redshift ◽  
Cluster Formation ◽  
Mass Function ◽  
Cosmological Simulations ◽  
High Redshift Galaxies ◽  
Cluster Mass ◽  
Formation Efficiency ◽  
Redshift Galaxies

ABSTRACT We report the formation of bound star clusters in a sample of high-resolution cosmological zoom-in simulations of z ≥ 5 galaxies from the Feedback In Realistic Environments project. We find that bound clusters preferentially form in high-pressure clouds with gas surface densities over $10^4\, \mathrm{ M}_{\odot }\, {\rm pc}^{-2}$, where the cloud-scale star formation efficiency is near unity and young stars born in these regions are gravitationally bound at birth. These high-pressure clouds are compressed by feedback-driven winds and/or collisions of smaller clouds/gas streams in highly gas-rich, turbulent environments. The newly formed clusters follow a power-law mass function of dN/dM ∼ M−2. The cluster formation efficiency is similar across galaxies with stellar masses of ∼107–$10^{10}\, \mathrm{ M}_{\odot }$ at z ≥ 5. The age spread of cluster stars is typically a few Myr and increases with cluster mass. The metallicity dispersion of cluster members is ∼0.08 dex in $\rm [Z/H]$ and does not depend on cluster mass significantly. Our findings support the scenario that present-day old globular clusters (GCs) were formed during relatively normal star formation in high-redshift galaxies. Simulations with a stricter/looser star formation model form a factor of a few more/fewer bound clusters per stellar mass formed, while the shape of the mass function is unchanged. Simulations with a lower local star formation efficiency form more stars in bound clusters. The simulated clusters are larger than observed GCs due to finite resolution. Our simulations are among the first cosmological simulations that form bound clusters self-consistently in a wide range of high-redshift galaxies.

scholarly journals New methods for identifying Lyman continuum leakers and reionization-epoch analogues

2020 ◽  
Vol 498 (1) ◽  
pp. 164-180 ◽  
Author(s):  
Harley Katz ◽  
Dominika Ďurovčíková ◽  
Taysun Kimm ◽  
Joki Rosdahl ◽  
Jeremy Blaizot ◽  
...  
Keyword(s):  
Emission Line ◽  
Galaxy Formation ◽  
Dwarf Galaxy ◽  
High Redshift ◽  
Indirect Methods ◽  
High Redshift Galaxies ◽  
Lyman Continuum ◽  
The Universe ◽  
Ionization Parameter ◽  
Redshift Galaxies

ABSTRACT Identifying low-redshift galaxies that emit Lyman continuum radiation (LyC leakers) is one of the primary, indirect methods of studying galaxy formation in the epoch of reionization. However, not only has it proved challenging to identify such systems, it also remains uncertain whether the low-redshift LyC leakers are truly ‘analogues’ of the sources that reionized the Universe. Here, we use high-resolution cosmological radiation hydrodynamics simulations to examine whether simulated galaxies in the epoch of reionization share similar emission line properties to observed LyC leakers at z ∼ 3 and z ∼ 0. We find that the simulated galaxies with high LyC escape fractions (fesc) often exhibit high O32 and populate the same regions of the R23–O32 plane as z ∼ 3 LyC leakers. However, we show that viewing angle, metallicity, and ionization parameter can all impact where a galaxy resides on the O32–fesc plane. Based on emission line diagnostics and how they correlate with fesc, lower metallicity LyC leakers at z ∼ 3 appear to be good analogues of reionization-era galaxies. In contrast, local [S ii]-deficient galaxies do not overlap with the simulated high-redshift LyC leakers on the S ii Baldwin–Phillips–Terlevich (BPT) diagram; however, this diagnostic may still be useful for identifying leakers. We use our simulated galaxies to develop multiple new diagnostics to identify LyC leakers using infrared and nebular emission lines. We show that our model using only [C ii]158 μm and [O iii]88 μm can identify potential leakers from non-leakers from the local Dwarf Galaxy Survey. Finally, we apply this diagnostic to known high-redshift galaxies and find that MACS 1149_JD1 at z = 9.1 is the most likely galaxy to be actively contributing to the reionization of the Universe.

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