Extending the $H\alpha$ survey for the local volume galaxies

TL;DR

This paper presents new $H\alpha$ emission line images for 35 nearby galaxies, estimating their star formation rates and analyzing their morphological features, including a superthin galaxy with an exceptionally large axis ratio.

Contribution

It extends the $H\alpha$ survey to additional local volume galaxies, providing new flux measurements and star formation rate estimates for diverse galaxy types.

Findings

All galaxies have $\log[sSFR]$ below -0.4 Gyr$^{-1}$.

The superthin galaxy UGC 7321 has an extremely large axis ratio of 38.

New $H\alpha$ flux data enhances understanding of star formation in nearby galaxies.

Abstract

Images in the $H\alpha$ emission line are presented for 35 nearby objects observed with the 6-m BTA telescope. Three of them, NGC 3377, NGC 3384, and NGC 3390, are bright E and S0 galaxies, one is an edge-on Sd galaxy UGC 7321, two are remote globular clusters associated with M 31, and the rest are dwarf galaxies of morphological types dIr, dTr, dSph, BCD, and Sm. The measured $H\alpha$ fluxes are used to estimate the integral $(SFR)$ and specific $(sSFR)$ star formation rates for these galaxies. The values of $\log[sSFR]$ for all these objects lie below a limit of $-0.4$(Gyr$^{-1})$. We note that the emission disk for the nearest superthin edge-on galaxy UGC 7321 has an extremely large axis ratio of $a/b = 38.$