Evolution and Feedback Effects of High-z Star-Forming Galaxies

2015 ◽  
Vol 11 (A29B) ◽  
pp. 228-228
Author(s):  
Masami Ouchi
Keyword(s):  
Structure Formation ◽  
Gravitational Lensing ◽  
Formation Rate ◽  
Feedback Effect ◽  
Density Estimates ◽  
Feedback Effects ◽  
Planck Data ◽  
Star Forming ◽  
Deep Imaging ◽  
Open Question

AbstractI review the recent observational progresses of star-forming galaxies at a redshift up to z~10. Inconjunction with gravitational lensing magnifications, deep HST observations obtain first density estimates of UV continuum radiation given by young massive stars, and reveal that the star-formation rate density (SFRD)continuously decreases from z~2-3 to z~10. This SFRD decrease towards high-z should be explained by thecombination of the cosmic structure formation and radiative cooling+feedback effects in a halo. To decouple thecontribution of the cosmic structure formation from the SFRD decrease, the stellar-to-halo mass ratios (SHMR) ofhigh-z galaxies are derived by intensive clustering analyses with HST and Subaru survey data. The SHMR-halo massrelation shows a clear evolution from z~0 to 6, suggesting that the cooling and feedback effects are different betweenthe present and early epochs of the cosmic history. By deep imaging and spectroscopic observations, feedbacksignatures are found in 10-100 kpc-scale outflow of ionized oxgen gas identified around star-forming galaxies with andwithout an AGN heating. There are similarly-large hydrogen Lyα halos and blobs associated with high-z star-forminggalaxies, but the physical origin of these Lyα halos and blobs is an open question. At z≳6, UV radiation of ionizingphotons produced by star-forming galaxies contribute to the cosmic reionization, while it is thought that the UVradiation prevent formation of next generation stars in dwarf galaxies at the early cosmic epoch, which works as acosmological feedback effect. I discuss this reionizations cosmological feedback effect with the up-to-date resultsfrom the HST and Planck data.

scholarly journals SCUBA-2 overdensities associated with candidate protoclusters selected from Planck data

2020 ◽  
Vol 494 (4) ◽  
pp. 5985-5991
Author(s):  
T Cheng ◽  
D L Clements ◽  
J Greenslade ◽  
J Cairns ◽  
P Andreani ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Intermediate Level ◽  
Planck Data ◽  
Star Forming ◽  
Compact Source ◽  
Number Counts ◽  
Compact Sources

ABSTRACT We measure the 850-μm source densities of 46 candidate protoclusters selected from the Planck high-z catalogue (PHz) and the Planck Catalogue of Compact Sources (PCCS) that were followed up with Herschel-SPIRE and SCUBA-2. This paper aims to search for overdensities of 850-μm sources in order to select the fields that are most likely to be genuine protoclusters. Of the 46 candidate protoclusters, 25 have significant overdensities (>5 times the field counts), 11 have intermediate overdensities (3–5 times the field counts), and 10 have no overdensity (<3 times the field counts) of 850-μm sources. We find that the enhanced number densities are unlikely to be the result of sample variance. Compared with the number counts of another sample selected from Planck’s compact source catalogues, this [PHz + PCCS]-selected sample has a higher fraction of candidate protoclusters with significant overdensities, though both samples show overdensities of 850-μm sources above intermediate level. Based on the estimated star formation rate densities (SFRDs), we suggest that both samples can efficiently select protoclusters with starbursting galaxies near the redshift at which the global field SFRD peaks (2 < z < 3). Based on the confirmation of overdensities found here, future follow-up observations on other PHz targets may greatly increase the number of genuine dusty star-forming galaxy-rich clusters/protoclusters.

scholarly journals Physics of a clumpy lensed galaxy at z = 1.6

2018 ◽  
Vol 619 ◽  
pp. A15 ◽  
Author(s):  
M. Girard ◽  
M. Dessauges-Zavadsky ◽  
D. Schaerer ◽  
J. Richard ◽  
K. Nakajima ◽  
...  
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
Near Infrared ◽  
High Redshift ◽  
Formation Rate ◽  
Far Infrared ◽  
Rotating Disk ◽  
Cluster Galaxy ◽  
Star Forming ◽  
The Galaxy

Observations have shown that massive star-forming clumps are present in the internal structure of high-redshift galaxies. One way to study these clumps in detail with a higher spatial resolution is by exploiting the power of strong gravitational lensing which stretches images on the sky. In this work, we present an analysis of the clumpy galaxy A68-HLS115 at z = 1.5858, located behind the cluster Abell 68, but strongly lensed by a cluster galaxy member. Resolved observations with SINFONI/VLT in the near-infrared (NIR) show Hα, Hβ, [NII], and [OIII] emission lines. Combined with images covering the B band to the far-infrared (FIR) and CO(2–1) observations, this makes this galaxy one of the only sources for which such multi-band observations are available and for which it is possible to study the properties of resolved star-forming clumps and to perform a detailed analysis of the integrated properties, kinematics, and metallicity. We obtain a stability of υrot/σ0 = 2.73 by modeling the kinematics, which means that the galaxy is dominated by rotation, but this ratio also indicates that the disk is marginally stable. We find a high intrinsic velocity dispersion of 80 ± 10 km s−1 that could be explained by the high gas fraction of fgas = 0.75 ± 0.15 observed in this galaxy. This high fgas and the observed sSFR of 3.12 Gyr−1 suggest that the disk turbulence and instabilities are mostly regulated by incoming gas (available gas reservoir for star formation). The direct measure of the Toomre stability criterion of Qcrit = 0.70 could also indicate the presence of a quasi-stable thick disk. Finally, we identify three clumps in the Hα map which have similar velocity dispersions, metallicities, and seem to be embedded in the rotating disk. These three clumps contribute together to ∼40% on the SFRHα of the galaxy and show a star formation rate density about ∼100 times higher than HII regions in the local Universe.

scholarly journals The discovery of the most UV–Ly α luminous star-forming galaxy: a young, dust- and metal-poor starburst with QSO-like luminosities

2020 ◽  
Vol 499 (1) ◽  
pp. L105-L110
Author(s):  
R Marques-Chaves ◽  
J Álvarez-Márquez ◽  
L Colina ◽  
I Pérez-Fournon ◽  
D Schaerer ◽  
...  
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
Active Galactic Nucleus ◽  
Star Formation Rate ◽  
High Redshift ◽  
Formation Rate ◽  
Star Forming ◽  
Evolutionary Scheme ◽  
Intense Burst

ABSTRACT We report the discovery of BOSS-EUVLG1 at z = 2.469, by far the most luminous, almost un-obscured star-forming galaxy known at any redshift. First classified as a QSO within the Baryon Oscillation Spectroscopic Survey, follow-up observations with the Gran Telescopio Canarias reveal that its large luminosity, MUV ≃ −24.40 and log(LLyα/erg s–1) ≃ 44.0, is due to an intense burst of star formation, and not to an active galactic nucleus or gravitational lensing. BOSS-EUVLG1 is a compact (reff ≃ 1.2 kpc), young (4–5 Myr) starburst with a stellar mass log(M*/M⊙) = 10.0 ± 0.1 and a prodigious star formation rate of ≃1000 M⊙ yr−1. However, it is metal- and dust-poor [12 + log(O/H) = 8.13 ± 0.19, E(B – V) ≃ 0.07, log(LIR/LUV) < −1.2], indicating that we are witnessing the very early phase of an intense starburst that has had no time to enrich the ISM. BOSS-EUVLG1 might represent a short-lived (<100 Myr), yet important phase of star-forming galaxies at high redshift that has been missed in previous surveys. Within a galaxy evolutionary scheme, BOSS-EUVLG1 could likely represent the very initial phases in the evolution of massive quiescent galaxies, even before the dusty star-forming phase.

scholarly journals Unveiling forming star clusters in the young Universe

2019 ◽  
Vol 14 (S351) ◽  
pp. 233-237
Author(s):  
E. Vanzella ◽  
F. Calura ◽  
M. Meneghetti ◽  
G. B. Caminha ◽  
A. Mercurio ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Gravitational Lensing ◽  
Massive Star ◽  
High Redshift ◽  
Star Clusters ◽  
Star Forming ◽  
Strong Gravitational Lensing ◽  
Deep Imaging ◽  
Look Back

AbstractThe identification of young massive star clusters (YMCs) at high redshift is becoming a real fact. We present recent results from Hubble deep imaging and VLT/ MUSE - X-Shooter observations boosted by strong gravitational lensing. We report on two parsec-scale star-forming systems at z = 6.145 and 2.37 (>10 Gyrs of look back time) currently representing the best candidate high-z YMCs. All of this also implies that the search for globular cluster precursors has already begun.

scholarly journals Giant star-forming clumps?

2020 ◽  
Vol 495 (1) ◽  
pp. L1-L6 ◽  
Author(s):  
R J Ivison ◽  
J Richard ◽  
A D Biggs ◽  
M A Zwaan ◽  
E Falgarone ◽  
...  
Keyword(s):  
Star Formation ◽  
Spatial Scale ◽  
Gravitational Lensing ◽  
Spatial Scales ◽  
Formation Rate ◽  
Dust Emission ◽  
Giant Molecular Clouds ◽  
Giant Star ◽  
Star Forming ◽  
Dusty Galaxies

ABSTRACT With the spatial resolution of the Atacama Large Millimetre Array (ALMA), dusty galaxies in the distant Universe typically appear as single, compact blobs of dust emission, with a median half-light radius, ≈1 kpc. Occasionally, strong gravitational lensing by foreground galaxies or galaxy clusters has probed spatial scales 1–2 orders of magnitude smaller, often revealing late-stage mergers, sometimes with tantalizing hints of sub-structure. One lensed galaxy in particular, the Cosmic Eyelash at z = 2.3, has been cited extensively as an example of where the interstellar medium exhibits obvious, pronounced clumps, on a spatial scale of ≈100 pc. Seven orders of magnitude more luminous than giant molecular clouds in the local Universe, these features are presented as circumstantial evidence that the blue clumps observed in many z ∼ 2–3 galaxies are important sites of ongoing star formation, with significant masses of gas and stars. Here, we present data from ALMA which reveal that the dust continuum of the Cosmic Eyelash is in fact smooth and can be reproduced using two Sérsic profiles with effective radii, 1.2 and 4.4 kpc, with no evidence of significant star-forming clumps down to a spatial scale of ≈80 pc and a star formation rate of <3 M⊙ yr−1.

scholarly journals SDSS J1059+4251, a Highly Magnified z ∼ 2.8 Star-forming Galaxy: ESI Observations of the Rest-frame UV Spectrum

2021 ◽  
Vol 922 (2) ◽  
pp. 187
Author(s):  
Annalisa Citro ◽  
Dawn K. Erb ◽  
Max Pettini ◽  
Matthew W. Auger ◽  
George D. Becker ◽  
...  
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
Rest Frame ◽  
Signal To Noise Ratio ◽  
High Redshift ◽  
Formation Rate ◽  
High Signal ◽  
Uv Spectrum ◽  
Star Forming ◽  
High Data

Abstract Detailed analyses of high-redshift galaxies are challenging because these galaxies are faint, but this difficulty can be overcome with gravitational lensing, in which the magnification of the flux enables spectroscopy with a high signal-to-noise ratio (S/N). We present the rest-frame ultraviolet (UV) Keck Echellette Spectrograph and Imager (ESI) spectrum of the newly discovered z = 2.79 lensed galaxy SDSS J1059+4251. With an observed magnitude F814W = 18.8 and a magnification factor μ = 31 ± 3, J1059+4251 is both highly magnified and intrinsically luminous, about two magnitudes brighter than M UV * at z ∼ 2–3. With a stellar mass M * = (3.22 ± 0.20) × 1010 M ⊙, star formation rate SFR = 50 ± 7 M⊙ yr−1, and stellar metallicity Z * ≃ 0.15–0.5 Z ⊙, J1059+4251 is typical of bright star-forming galaxies at similar redshifts. Thanks to the high S/N and the spectral resolution of the ESI spectrum, we are able to separate the interstellar and stellar features and derive properties that would be inaccessible without the aid of the lensing. We find evidence of a gas outflow with speeds up to −1000 km s−1, and of an inflow that is probably due to accreting material seen along a favorable line of sight. We measure relative elemental abundances from the interstellar absorption lines and find that α-capture elements are overabundant compared to iron-peak elements, suggestive of rapid star formation. However, this trend may also be affected by dust depletion. Thanks to the high data quality, our results represent a reliable step forward in the characterization of typical galaxies at early cosmic epochs.

scholarly journals Properties of galaxies with an offset between the position angles of the major kinematic and photometric axes

2020 ◽  
Vol 634 ◽  
pp. A26 ◽  
Author(s):  
L. S. Pilyugin ◽  
E. K. Grebel ◽  
I. A. Zinchenko ◽  
J. M. Vílchez ◽  
F. Sakhibov ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Velocity Fields ◽  
Oxygen Abundance ◽  
Star Forming ◽  
Measured Position ◽  
Central Oxygen ◽  
Straight Lines

We derive the photometric, kinematic, and abundance characteristics of 18 star-forming MaNGA galaxies with fairly regular velocity fields and surface brightness distributions and with a large offset between the measured position angles of the major kinematic and photometric axes, ΔPA ≳ 20°. The aim is to examine if there is any other distinctive characteristic common to these galaxies. We found morphological signs of interaction in some (in 11 out of 18) but not in all galaxies. The observed velocity fields show a large variety; the maps of the isovelocities vary from an hourglass-like appearance to a set of straight lines. The position angles of the major kinematic axes of the stellar and gas rotations are close to each other. The values of the central oxygen abundance, radial abundance gradient, and star formation rate are distributed within the intervals defined by galaxies with small (no) ΔPA of similar mass. Thus, we do not find any specific characteristic common to all galaxies with large ΔPA. Instead, the properties of these galaxies are similar to those of galaxies with small (no) ΔPA. This suggests that either the reason responsible for the large ΔPA does not influence other characteristics or the galaxies with large ΔPA do not share a common origin, they can, instead, originate through different channels.

scholarly journals Characterizing the abundance, properties, and kinematics of the cool circumgalactic medium of galaxies in absorption with SDSS DR16

2021 ◽  
Vol 504 (1) ◽  
pp. 65-88
Author(s):  
Abhijeet Anand ◽  
Dylan Nelson ◽  
Guinevere Kauffmann
Keyword(s):  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Gas Absorption ◽  
Dark Matter Halo ◽  
Star Forming ◽  
Sky Survey ◽  
Optical Continuum ◽  
Circumgalactic Medium ◽  
Emission Line Galaxies ◽  
Red Galaxies

ABSTRACT In order to study the circumgalactic medium (CGM) of galaxies we develop an automated pipeline to estimate the optical continuum of quasars and detect intervening metal absorption line systems with a matched kernel convolution technique and adaptive S/N criteria. We process ∼ one million quasars in the latest Data Release 16 (DR16) of the Sloan Digital Sky Survey (SDSS) and compile a large sample of ∼ 160 000 Mg ii absorbers, together with ∼ 70 000 Fe ii systems, in the redshift range 0.35 < zabs < 2.3. Combining these with the SDSS DR16 spectroscopy of ∼1.1 million luminous red galaxies (LRGs) and ∼200 000 emission line galaxies (ELGs), we investigate the nature of cold gas absorption at 0.5 < z < 1. These large samples allow us to characterize the scale dependence of Mg ii with greater accuracy than in previous work. We find that there is a strong enhancement of Mg ii absorption within ∼50 kpc of ELGs, and the covering fraction within 0.5rvir of ELGs is 2–5 times higher than for LRGs. Beyond 50 kpc, there is a sharp decline in Mg ii for both kinds of galaxies, indicating a transition to the regime where the CGM is tightly linked with the dark matter halo. The Mg ii-covering fraction correlates strongly with stellar mass for LRGs, but weakly for ELGs, where covering fractions increase with star formation rate. Our analysis implies that cool circumgalactic gas has a different physical origin for star-forming versus quiescent galaxies.

scholarly journals The effects of star formation history in the SFR–M* relation of H ii galaxies

2020 ◽  
Vol 500 (3) ◽  
pp. 3240-3253
Author(s):  
Amanda R Lopes ◽  
Eduardo Telles ◽  
Jorge Melnick
Keyword(s):  
Star Formation ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Star Formation History ◽  
Spectral Energy ◽  
Distribution Fitting ◽  
Good Tool ◽  
Star Forming ◽  
Additional Information ◽  
Star Formation Histories

ABSTRACT We discuss the implications of assuming different star formation histories (SFH) in the relation between star formation rate (SFR) and mass derived by the spectral energy distribution fitting (SED). Our analysis focuses on a sample of H ii galaxies, dwarf starburst galaxies spectroscopically selected through their strong narrow emission lines in SDSS DR13 at z < 0.4, cross-matched with photometric catalogues from GALEX, SDSS, UKIDSS, and WISE. We modelled and fitted the SEDs with the code CIGALE adopting different descriptions of SFH. By adding information from different independent studies, we find that H ii galaxies are best described by episodic SFHs including an old (10 Gyr), an intermediate age (100−1000 Myr) and a recent population with ages < 10 Myr. H ii galaxies agree with the SFR−M* relation from local star-forming galaxies, and only lie above such relation when the current SFR is adopted as opposed to the average over the entire SFH. The SFR−M* demonstrated not to be a good tool to provide additional information about the SFH of H ii galaxies, as different SFH present a similar behaviour with a spread of <0.1 dex.

scholarly journals Morphometry as a probe of the evolution of jellyfish galaxies: evidence of broadening in the surface brightness profiles of ram-pressure stripping candidates in the multicluster system A901/A902

2020 ◽  
Vol 500 (1) ◽  
pp. 40-53
Author(s):  
Fernanda Roman-Oliveira ◽  
Ana L Chies-Santos ◽  
Fabricio Ferrari ◽  
Geferson Lucatelli ◽  
Bruno Rodríguez Del Pino
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Quantitative Measurement ◽  
Star Formation Rate ◽  
Hubble Space Telescope ◽  
Formation Rate ◽  
Structural Evolution ◽  
Star Forming ◽  
Irregular Structures ◽  
Ram Pressure

ABSTRACT We explore the morphometric properties of a group of 73 ram-pressure stripping candidates in the A901/A902 multicluster system, at z∼ 0.165, to characterize the morphologies and structural evolution of jellyfish galaxies. By employing a quantitative measurement of morphometric indicators with the algorithm morfometryka on Hubble Space Telescope (F606W) images of the galaxies, we present a novel morphology-based method for determining trail vectors. We study the surface brightness profiles and curvature of the candidates and compare the results obtained with two analysis packages, morfometryka and iraf/ellipse on retrieving information of the irregular structures present in the galaxies. Our morphometric analysis shows that the ram-pressure stripping candidates have peculiar concave regions in their surface brightness profiles. Therefore, these profiles are less concentrated (lower Sérsic indices) than other star-forming galaxies that do not show morphological features of ram-pressure stripping. In combination with morphometric trail vectors, this feature could both help identify galaxies undergoing ram-pressure stripping and reveal spatial variations in the star formation rate.

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