Effect of Dust Extinction on Estimating the Star Formation Rate of Galaxies: Lyman Continuum Extinction

2001 ◽  
Vol 555 (2) ◽  
pp. 613-624 ◽  
Author(s):  
Akio K. Inoue ◽  
Hiroyuki Hirashita ◽  
Hideyuki Kamaya
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Dust Extinction ◽  
Lyman Continuum

scholarly journals ULTRA-FAINT ULTRAVIOLET GALAXIES ATz∼ 2 BEHIND THE LENSING CLUSTER A1689: THE LUMINOSITY FUNCTION, DUST EXTINCTION, AND STAR FORMATION RATE DENSITY

2013 ◽  
Vol 780 (2) ◽  
pp. 143 ◽  
Author(s):  
Anahita Alavi ◽  
Brian Siana ◽  
Johan Richard ◽  
Daniel P. Stark ◽  
Claudia Scarlata ◽  
...  
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Dust Extinction

scholarly journals THE OBSERVED RELATION BETWEEN STELLAR MASS, DUST EXTINCTION, AND STAR FORMATION RATE IN LOCAL GALAXIES

2013 ◽  
Vol 763 (2) ◽  
pp. 92 ◽  
Author(s):  
H. J. Zahid ◽  
R. M. Yates ◽  
L. J. Kewley ◽  
R. P. Kudritzki
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Mass ◽  
Dust Extinction

scholarly journals The VANDELS survey: the role of ISM and galaxy physical properties in the escape of Lyα emission in z ∼ 3.5 star-forming galaxies

2019 ◽  
Vol 631 ◽  
pp. A19 ◽  
Author(s):  
F. Marchi ◽  
L. Pentericci ◽  
L. Guaita ◽  
M. Talia ◽  
M. Castellano ◽  
...  
Keyword(s):  
Star Formation ◽  
Physical Properties ◽  
Emission Line ◽  
Column Density ◽  
Star Formation Rate ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Stellar Mass ◽  
Dust Extinction

Aims. We wish to investigate the physical properties of a sample of Lyα emitting galaxies in the VANDELS survey, with particular focus on the role of kinematics and neutral hydrogen column density in the escape and spatial distribution of Lyα photons. Methods. From all the Lyα emitting galaxies in the VANDELS Data Release 2 at 3.5 ≲ z ≲ 4.5, we selected a sample of 52 galaxies that also have a precise systemic redshift determination from at least one nebular emission line (HeII or CIII]). For these galaxies, we derived different physical properties (stellar mass, age, dust extinction, and star formation rate) from spectral energy distribution (SED) fitting of the exquisite multiwavelength photometry available in the VANDELS fields, using the dedicated spectral modeling tool BEAGLE and the UV β slope from the observed photometry. We characterized the Lyα emission in terms of kinematics, equivalent width (EW), full width at half-maximum, and spatial extension and then estimated the velocity of the neutral outflowing gas. The ultra-deep VANDELS spectra (up to 80 h on-source integration) enable this for individual galaxies without the need to rely on stacks. We then investigated the correlations between the Lyα properties and the other measured properties to study how they affect the shape and intensity of Lyα emission. Results. We reproduce some of the well-known correlations between Lyα EW and stellar mass, dust extinction, and UV β slope, in the sense that the emission line appears brighter in galaxies with lower mass that are less dusty and bluer. We do not find any correlation with the SED-derived star formation rate, while we find that galaxies with brighter Lyα tend to be more compact in both UV and in Lyα. Our data reveal an interesting correlation between the Lyα velocity offset and the shift of the interstellar absorption lines with respect to the systemic redshift, observed for the first time at high redshifts: galaxies with higher interstellar medium (ISM) outflow velocities show smaller Lyα velocity shifts. We interpret this relation in the context of the shell-model scenario, where the velocity of the ISM and the HI column density contribute together in determining the Lyα kinematics. In support to our interpretation, we observe that galaxies with high HI column densities have much more extended Lyα spatial profiles; this is a sign of increased scattering. However, we do not find any evidence that the HI column density is related to any other physical properties of the galaxies, although this might be due in part to the limited range of parameters that our sample spans.

scholarly journals A LOFAR-IRAS cross-match study: the far-infrared radio correlation and the 150 MHz luminosity as a star-formation rate tracer

2019 ◽  
Vol 631 ◽  
pp. A109 ◽  
Author(s):  
L. Wang ◽  
F. Gao ◽  
K. J. Duncan ◽  
W. L. Williams ◽  
M. Rowan-Robinson ◽  
...  
Keyword(s):  
Star Formation ◽  
Rest Frame ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Value Added ◽  
Far Infrared ◽  
Star Forming ◽  
Dust Extinction ◽  
Best Fit ◽  
Cross Match

Aims. We aim to study the far-infrared radio correlation (FIRC) at 150 MHz in the local Universe (at a median redshift ⟨z⟩∼0.05) and improve the use of the rest-frame 150 MHz luminosity, L150, as a star-formation rate (SFR) tracer, which is unaffected by dust extinction. Methods. We cross-match the 60 μm selected Revised IRAS Faint Source Survey Redshift (RIFSCz) catalogue and the 150 MHz selected LOFAR value-added source catalogue in the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Spring Field. We estimate L150 for the cross-matched sources and compare it with the total infrared (IR) luminosity, LIR, and various SFR tracers. Results. We find a tight linear correlation between log L150 and log LIR for star-forming galaxies, with a slope of 1.37. The median qIR value (defined as the logarithm of the LIR to L150 ratio) and its rms scatter of our main sample are 2.14 and 0.34, respectively. We also find that log L150 correlates tightly with the logarithm of SFR derived from three different tracers, i.e., SFRHα based on the Hα line luminosity, SFR60 based on the rest-frame 60 μm luminosity and SFRIR based on LIR, with a scatter of 0.3 dex. Our best-fit relations between L150 and these SFR tracers are, log L150 (L⊙) = 1.35(±0.06) × log SFRHα (M⊙ yr−1) + 3.20(±0.06), log L150 (L⊙) = 1.31(±0.05) × log SFR60 (M⊙ yr−1) + 3.14(±0.06), and log L150 (L⊙) = 1.37 (±0.05) × log SFRIR (M⊙ yr−1) + 3.09(±0.05), which show excellent agreement with each other.

scholarly journals Obscured star formation atz= 0.84 with HiZELS: the relationship between star formation rate and Hα or ultraviolet dust extinction

2010 ◽  
Vol 402 (3) ◽  
pp. 2017-2030 ◽  
Author(s):  
Timothy Garn ◽  
David Sobral ◽  
Philip N. Best ◽  
James E. Geach ◽  
Ian Smail ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Dust Extinction ◽  
The Relationship

scholarly journals Luminous Stellar Content of the Galaxy: Inferences from Radio and Infrared Data

1986 ◽  
Vol 116 ◽  
pp. 479-495
Author(s):  
P. G. Mezger
Keyword(s):  
Star Formation ◽  
Reasonable Agreement ◽  
Star Formation Rate ◽  
Galactic Disk ◽  
Formation Rate ◽  
Stellar Content ◽  
Lyman Continuum ◽  
The Galaxy ◽  
Low Mass ◽  
Infrared Data

Lyman continuum (Lyc) photon production rates can be estimated from radio free-free emission and used to estimate the star formation rate (SFR) of 0 stars. If this SFR is linked to the total SFR through a constant IMF (m ≳0.1 m⊙) one derives for our Galaxy a present-day SFR of ∼10 m⊙ yr−1, which is close to the average SFR over the age of the galactic disk. This is difficult to reconcile with a formation law of the form SFR φ∝Mgask with k>0 which yields SFRs which decrease with time. Even more severe is the fact that the mass distribution of the galactic disk cannot be reproduced by the present-day SFR with a constant IMF. Bimodal star formation, however, reduces the rate at which matter is permanently locked up in low mass and dead stars by nearly a factor of three, and gets reasonable agreement between the present-day distribution of stellar mass and lock-up rate. Bimodal star formation means that stars with m >0.1 m⊙ form in the interarm region while in spiral arms induced star formation produces only stars with m >mc ∼2–3 m⊙.

scholarly journals Enhanced X-ray emission from candidate Lyman continuum emitting galaxies

2019 ◽  
Vol 487 (3) ◽  
pp. 4093-4101 ◽  
Author(s):  
J Bluem ◽  
P Kaaret ◽  
A Prestwich ◽  
M Brorby
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Emission Lines ◽  
X Rays ◽  
Blue Colour ◽  
X Ray ◽  
Near Ultraviolet ◽  
Lyman Continuum ◽  
X Ray Binaries

ABSTRACT X-ray binaries may have helped reionize the early Universe by enabling Lyman continuum escape. We analysed a set of eight local galaxies that are potential Lyman leaking galaxies, identified by a blue colour and weak emission lines, using Chandra X-ray observations. Five of the galaxies feature X-ray sources, while three galaxies are not significantly detected in X-rays. X-ray luminosities were found for the galaxies and X-ray sources. Four of the galaxies have elevated X-ray luminosity versus what would be expected based on star formation rate and metallicity. The presence of detected X-ray sources within the galaxies is found to correlate with the ratio of the star formation rate estimated from the near-ultraviolet flux to that estimated from the infrared. This implies reduced obscuration due to dust in the galaxies with X-ray sources. These results support the idea that X-ray binaries may be an important part of the process of reionziation.

scholarly journals An uncertainty principle for star formation – V. The influence of dust extinction on star formation rate tracer lifetimes and the inferred molecular cloud lifecycle

2020 ◽  
Vol 497 (4) ◽  
pp. 5076-5089
Author(s):  
Daniel T Haydon ◽  
Yusuke Fujimoto ◽  
Mélanie Chevance ◽  
J M Diederik Kruijssen ◽  
Mark R Krumholz ◽  
...  
Keyword(s):  
Star Formation ◽  
Time Scales ◽  
Molecular Cloud ◽  
Column Density ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Disc Galaxy ◽  
Dust Extinction ◽  
Stellar Feedback ◽  
Emission Time

ABSTRACT Recent observational studies aiming to quantify the molecular cloud lifecycle require the use of known ‘reference time-scales’ to turn the relative durations of different phases of the star formation process into absolute time-scales. We previously constrained the characteristic emission time-scales of different star formation rate (SFR) tracers, as a function of the SFR surface density and metallicity. However, we omitted the effects of dust extinction. Here, we extend our suite of SFR tracer emission time-scales by accounting for extinction, using synthetic emission maps of a high-resolution hydrodynamical simulation of an isolated, Milky Way-like disc galaxy. The stellar feedback included in the simulation is inefficient compared to observations, implying that it represents a limiting case in which the duration of embedded star formation (and the corresponding effect of extinction) is overestimated. Across our experiments, we find that extinction mostly decreases the SFR tracer emission time-scale, changing the time-scales by factors of 0.04–1.74, depending on the gas column density. UV filters are more strongly affected than H α filters. We provide the limiting correction factors as a function of the gas column density and flux sensitivity limit for a wide variety of SFR tracers. Applying these factors to observational characterizations of the molecular cloud lifecycle produces changes that broadly fall within the quoted uncertainties, except at high kpc-scale gas surface densities ($\Sigma _{\rm g}\gtrsim 20~{\mathrm{M_{\odot }\, pc^{-2}}}$). Under those conditions, correcting for extinction may decrease the measured molecular cloud lifetimes and feedback time-scales, which further strengthens previous conclusions that molecular clouds live for a dynamical time and are dispersed by early, pre-supernova feedback.

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