Hα and UV luminosities and star formation rates in a large sample of luminous compact galaxies

2016

Astrophys Space Sci

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We study Hα, far-and near-ultraviolet luminosity functions (LF) of the sample of 795 luminous compact star-forming galaxies with z < 0.65. The parameters of optimal functions for LFs are obtained using the maximum likelihood method and the accuracy of fitting is estimated with the χ 2 method. We find that these LFs cannot be reproduced by the Schechter function because of an excess of very luminous galaxies. On the other hand, the Saunders function, the log-normal distribution and some new related functions are good approximations of LFs. The fact that LFs are not reproduced by the Schechter function can be explained by the propagating star formation. This may result in an excess of luminous starbursts with the mass of a young stellar population above 2 × 10 8 M ⊙ as compared to the LF of the quiescent galaxies. The most luminous compact galaxies are characterised by Hα luminosities of ≥ 5 × 10 42 erg s −1 and star formation rates of ≥ 40 M ⊙ yr −1 .

“…Similarly Parnovsky, Izotova & Izotov (2013) found the excess of galaxies at the bright end of the Hα, FUV and NUV LFs for LCGs. In this paper we study LFs of this sample in more detail.…”

Section: Commonly Used Lf Approximationsmentioning

confidence: 54%

Luminosity function of luminous compact star-forming galaxies

2016

Astrophys Space Sci

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“…We use these coefficients to calculate SFR values for the sample of LCGs. According to Parnovsky et al (2013) the statistical dependence of the luminosity of an individual galaxy on its parameters has the form Parnovsky et al (2013) imply that Hα, FUV and NUV emissions in LCGs are produced by the same young stellar populations. These facts justify the applicability of the m and T estimation from the luminosities in different bands.…”

Section: Description Of the Methodsmentioning

confidence: 99%

“…Because the radiation of galaxies is reduced by dust extinction, we applied reddening corrections to Hα and UV band fluxes using Cardelli et al (1989) reddening law. All Hα emission line luminosities are also corrected for aperture (see details in Parnovsky et al 2013).…”

Section: Sample and Subsamplesmentioning

confidence: 99%

“…In Parnovsky et al (2013) the sample of LCGs was splitted into two subsamples of "regular" galaxies with the round shape and "irregular" galaxies with some sign of disturbed morphology suggesting the presence of two or more star-forming regions and their interaction. To clarify the impact of the LCG's morphology on the obtained parameters we instead of these two subsamples produce seven subsamples on the base of detailed visual examination of galaxies morphology on SDSS images.…”

Section: Sample and Subsamplesmentioning

confidence: 99%

“…II -"irregular" galaxies. These subsamples are practically the same as the subsamples used by papers Izotov et al (2011) and Parnovsky et al (2013). III -"irregular" galaxies with a single star-forming region.…”

Section: Sample and Subsamplesmentioning

confidence: 99%

See 2 more Smart Citations

A technique for estimation of starburst masses and ages in luminous compact galaxies

2013

Astrophys Space Sci

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We propose a technique for estimation of the mass m of the young stellar population and the starburst age T in luminous compact galaxies (LCGs). For this purpose we use LCG Hα emission line luminosities from the Sloan Digital Sky Survey (SDSS) spectra and Galaxy Evolution Explorer (GALEX) FUV and NUV continuum luminosities. The method is intended for quick estimation of m and T in large galaxy samples and does not require spectral energy distribution (SED) fitting. Estimated m and T for the sample of about 550 LCGs are compared with the same values derived from the SED fitting in the wavelength range λλ 3800 -9200Å. We obtain the average differences in log m and T of 0.27 and 0.87 Myr, respectively. This technique could be used for selection of galaxies with desired ranges of m and T or for reducing a range of parameter variations in SED fitting.

Radio emission at 1.4 GHz from luminous compact galaxies

2015

Astron Nachr

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We analyse the properties of the 1.4 GHz continuum emission in 52 star-forming compact luminous galaxies (LCGs). The fluxes of the 1.4 GHz thermal (free-free) component are derived from the extinction-and aperture-corrected fluxes of the Hα emission line. The fraction of the thermal 1.4 GHz emission is shown to be in the range of 2-52 % with a median value of about 15-17 %, and its distribution is close to a log-normal one. Both the thermal and non-thermal radio continuum luminosities are shown to be proportional to the masses of the young stellar population of the LCGs. We discuss the approximation of the ratio of the 1.4 GHz luminosity-to-the mass of the young stellar population as a function of starburst age. The derived approximation is shown to be similar but less clearly defined compared to ones obtained previously for LCGs from their Hα and UV continuum luminosities.