The HⅠ Gas Fraction Scaling Relation of the Green Pea Galaxies

【摘要】 Green Pea galaxies are compact galaxies with high star formation rates. However, limited samples of Green Pea galaxies have H I 21 cm measurements. Whether the H I gas fraction（ fH I≡ MH I/M_★） of Green Pea galaxies follows the existing scaling relations between the fH Iand NUV-r color or linear combinations of color and other physical quantities needs checking. Using archival data of H I 21 cm observations, we investigate the scaling relation of the NUV-r color with the MH I/M_★of 38 Green Pea galaxies, including 17 detections and 21 nondetections. The H I to stellar mass ratios（ fH I） of Green Pea galaxies deviate from the polynomial form, where a higher H I gas fraction is predicted given the current NUV-r color, even with the emission lines removed. The blue sources（NUV-r < 1） from the comparison sample（ALFALFA-SDSS） follow a similar trend. The H I gas fraction scaling relations with linear combination forms of-0.34（N UV-r）-0.64 log(μ_★,z)+5.9 and-0.77 log_μ★, i+ 0.26logS FRM_★ +8.53, better predict the H I gas fraction of the Green Pea galaxies. In order to obtain accurate linear combined forms, higher-resolution photometry from space-based telescopes is needed.更多还原

【Abstract】 Green Pea galaxies are compact galaxies with high star formation rates. However, limited samples of Green Pea galaxies have H I 21 cm measurements. Whether the H I gas fraction（ fH I≡ MH I/M_★） of Green Pea galaxies follows the existing scaling relations between the fH Iand NUV-r color or linear combinations of color and other physical quantities needs checking. Using archival data of H I 21 cm observations, we investigate the scaling relation of the NUV-r color with the MH I/M_★of 38 Green Pea galaxies, including 17 detections and 21 nondetections. The H I to stellar mass ratios（ fH I） of Green Pea galaxies deviate from the polynomial form, where a higher H I gas fraction is predicted given the current NUV-r color, even with the emission lines removed. The blue sources（NUV-r < 1） from the comparison sample（ALFALFA-SDSS） follow a similar trend. The H I gas fraction scaling relations with linear combination forms of-0.34（N UV-r）-0.64 log(μ_★,z)+5.9 and-0.77 log_μ★, i+ 0.26logS FRM_★ +8.53, better predict the H I gas fraction of the Green Pea galaxies. In order to obtain accurate linear combined forms, higher-resolution photometry from space-based telescopes is needed.更多还原