Devasthal Fast Optical Telescope Observations of Wolf–Rayet Dwarf Galaxy Mrk 996

Journal of astrophysics and astronomy

S. Jaiswal1¹  A. Omar1¹ 

[1] Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital 263002, India.$$

关键词: Galaxies: dwarf;    galaxies: individual (Mrk 996);    galaxies: ISM;    galaxies: starburst;    galaxies: star formation rate;    ISM: H𝛼.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The Devasthal Fast Optical Telescope (DFOT) is a 1.3 meter aperture optical telescope, recently installed at Devasthal, Nainital. We present here the first results using an H𝛼 filter with this telescope on a Wolf–Rayet dwarf galaxy Mrk 996. The instrumental response and the H𝛼 sensitivity obtained with the telescope are (3.3 ± 0.3) × 10-15 erg s-1 cm-2/counts s-1 and 7.5 × 10-17 erg s-1 cm-2 arcsec-2 respectively. The H𝛼 flux and the equivalent width for Mrk 996 are estimated as (132 ± 37) × 10-14 erg s-1 cm-2 and ∼ 96 Å respectively. The star formation rate is estimated as 0.4 ± 0.1𝑀⊙ yr-1. Mrk 996 deviates from the radio-FIR correlation known for normal star forming galaxies with a deficiency in its radio continuum. The ionized gas as traced by Hα emission is found in a disk shape which is misaligned with respect to the old stellar disk. This misalignment is indicative of a recent tidal interaction in the galaxy. We believe that galaxy–galaxy tidal interaction is the main cause of the WR phase in Mrk 996.

【 授权许可】

Unknown