Stellar and dust properties in a sample of blue early type galaxies

Serbian Astronomical Journal

article

Deshmukh S.P.¹  Vagshette N.D.²  Patil M.K.³ 

[1] Department of Physics, Institute of Science;Department of Physics and Electronics;Swami Ramanand Teerth Marathwada University

关键词: Galaxies: star formation;    Galaxies: elliptical and lenticular;    cD;   

DOI  :  10.2298/SAJ2205023D

来源: Astronomical Observatory, Department of Astronomy, Belgrade

【 摘 要 】

This paper presents a comparative study of physical properties of a sample of 89 blueearly-type galaxies (ETGs) from the local universe by fitting SEDs to their multi-wavelength photometricand spectroscopic data. The detailed template-based SED fitting analysis using the MAGPHY S andSED3F IT codes on the interstellar dust extinction corrected UV-to-far-IR spectro-photometric dataenabled us to trace the evolutionary sequence of the blue ETGs on the color-magnitude diagram. Thisstudy evidenced a decreasing trend of the SFR, sSFR, dust mass, and dust mass fraction over thesequence from the SF - to - the Seyferts - to - the LINERs. The UV-optical colors also enabled us toestimate the look-back time of the last starburst phase in SF, Seyfert, and LINER galaxies, probablypointing towards the evolutionary sequence of the blue ETGs. Despite the blue colors and strongemission lines in the optical regime of the electromagnetic spectrum, the blue ETGs in the presentsample occupy a position off the main sequence, commonly known as the green valley, on the CMD plotand hence indicate the transitional state of their non-secular evolution. A marginal positive correlationwas noticed between SFR per unit dust mass and the temperature of the cool ISM. The declining trendof the cold dust temperature Tc over the sequence from the SF-to-Seyfert-to-LINER implies that theAGNs in the systems are not enough powerful to affect the cold component of the ISM.

【 授权许可】

CC BY-NC-ND