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.

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 CO Excitation, Molecular Gas Density, and Interstellar Radiation Field in Local and High-redshift Galaxies

2021 ◽  
Vol 909 (1) ◽  
pp. 56
Author(s):  
Daizhong Liu ◽  
Emanuele Daddi ◽  
Eva Schinnerer ◽  
Toshiki Saito ◽  
Adam Leroy ◽  
...  
Keyword(s):  
Radiation Field ◽  
High Redshift ◽  
Molecular Gas ◽  
Gas Density ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals MID-INFRARED SPECTROSCOPY OF SUBMILLIMETER GALAXIES: EXTENDED STAR FORMATION IN MASSIVE HIGH-REDSHIFT GALAXIES

2009 ◽  
Vol 699 (1) ◽  
pp. 667-685 ◽  
Author(s):  
Karín Menéndez-Delmestre ◽  
Andrew W. Blain ◽  
Ian Smail ◽  
Dave M. Alexander ◽  
Scott C. Chapman ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Star Formation ◽  
High Redshift ◽  
Mid Infrared ◽  
High Redshift Galaxies ◽  
Mid Infrared Spectroscopy ◽  
Submillimeter Galaxies ◽  
Redshift Galaxies

scholarly journals A LINK TO THE PAST: USING MARKOV CHAIN MONTE CARLO FITTING TO CONSTRAIN FUNDAMENTAL PARAMETERS OF HIGH-REDSHIFT GALAXIES

2012 ◽  
Vol 748 (2) ◽  
pp. 122 ◽  
Author(s):  
N. Pirzkal ◽  
B. Rothberg ◽  
Kim K. Nilsson ◽  
S. Finkelstein ◽  
Anton Koekemoer ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
High Redshift ◽  
High Redshift Galaxies ◽  
Fundamental Parameters ◽  
The Past ◽  
Redshift Galaxies

scholarly journals THE ALMA SPECTROSCOPIC SURVEY IN THEHUBBLEULTRA DEEP FIELD: MOLECULAR GAS RESERVOIRS IN HIGH-REDSHIFT GALAXIES

2016 ◽  
Vol 833 (1) ◽  
pp. 70 ◽  
Author(s):  
Roberto Decarli ◽  
Fabian Walter ◽  
Manuel Aravena ◽  
Chris Carilli ◽  
Rychard Bouwens ◽  
...  
Keyword(s):  
High Redshift ◽  
Molecular Gas ◽  
Gas Reservoirs ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

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.

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