2023/10/03 by Yogesh Chandola, Chandola, Yogesh, Di Li +23
Chemistry · Physics and Astronomy · #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Spectroscopy and Laser Applications #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2310.02202
openalex publication_date 2023/10/03 · openalex created_date 2023/10/05 · openalex updated_date 2026/08/01
We report measurements of H I content in 11 nearby, actively star-forming, blue compact dwarf galaxies (BCDs) from 21 cm observations with the Arecibo telescope. These BCDs, selected by their red (W2[4.6 μm]-W3[12 μm]>3.8 mag) and bright mid-infrared (MIR) emission (W4[22 μm]< 7.6 mag), have high specific star formation rates (median sSFR ∼10-7.8 yr-1), similar to high redshift galaxies. H I emission was detected in six sources. We analyze our new detections in the context of previous H I observations of 218 dwarf irregulars (dIs) and BCDs in the literature. The M\rm HI-M∗ relation resulting from our observations confirms the dominating fraction of H I gas among baryons in galaxies with lower stellar masses. This Arecibo BCD sample has significantly lower median H I depletion timescales (τ\rm HI∼ 0.3 Gyr) than other dIs/BCDs (∼ 6.3 Gyr) in the literature. The majority of the sources (10/11) in the Arecibo sample are very red in W1[3.4 μm]-W2[4.6 μm] colour (> 0.8 mag) implying the presence of warm dust. We investigate the relation of τ\rm HI with stellar mass (M∗) and sSFR. We find that τ\rm HI is significantly anti-correlated with M∗ for higher sSFR (>10-8.5 yr-1) and with sSFR for higher stellar mass (>107.5 \rm M\odot) dwarf galaxies. The high sSFR for the BCDs in the Arecibo observed sample is mainly due to their high atomic gas star formation efficiency (SFE) or low τ\rm HI. The low τ\rm HI or high SFE in these sources is possibly due to runaway star formation in compact and dense super star clusters.