THE GAS PHASE MASS METALLICITY RELATION FOR DWARF GALAXIES: DEPENDENCE ON STAR FORMATION RATE AND HI GAS MASS
THE GAS PHASE MASS METALLICITY RELATION FOR DWARF GALAXIES: DEPENDENCE ON STAR FORMATION RATE AND HI GAS MASS
复制标题
DOI：
10.1088/0004-637x/812/2/98
复制
发表时间：
2015-09
期刊：
影响因子：
--
通讯作者：
Jimmy;K. Tran;A. Saintonge;Gioacchino Accurso;S. Brough;P. Oliva-Altamirano;P. Oliva-Altamirano
中科院分区：
文献类型：
--
作者：
Jimmy;K. Tran;A. Saintonge;Gioacchino Accurso;S. Brough;P. Oliva-Altamirano;P. Oliva-Altamirano
利用甚大望远镜上的VIMOS IFU观测到的一个矮星系样本，我们研究了质量-金属丰度关系（MZR）作为恒星形成速率（FMRSFR）和hi -气体质量（FMRHI）的函数。我们将IFU数据与ALFALFA HI巡天与斯隆数字巡天（SDSS）交叉匹配的星系子样本相结合，研究了恒星质量范围106.6-108.8 M⊙的FMRSFR和FMRHI，金属丰度低至12 + log(O/H) = 7.67。我们发现MZR的1σ平均散射为0.05指数。FMRSFR的1σ平均散射（0.02指数）显著低于MZR。IFU观测到的星系与ALFALFA/SDSS星系在SFRs低于10−2.4 M⊙yr−1时的FMRSFR不一致，然而，这可能是我们在该范围内测量的局限性的结果。在FMRHI中发现最低的平均散射（0.01指数）。我们还发现IFU观测到的矮星系与ALFALFA/SDSS交叉匹配样本之间的FMRHI是一致的。我们引入了与FMR相对应的基本金属丰度光度，再次以SFR （FMLSFR）和HI-gas质量（FMLHI）表征。我们发现IFU观测到的矮星系样本与较大的ALFALFA/SDSS样本之间的FMLHI关系是一致的。然而，FMLHI关系的1σ散点在FMRHI场景下并没有得到改善。这使我们得出结论，FMRHI是物理驱动的基本金属丰度关系的最佳候选。
Using a sample of dwarf galaxies observed using the VIMOS IFU on the Very Large Telescope, we investigate the mass–metallicity relation (MZR) as a function of star formation rate (FMRSFR) as well as HI-gas mass (FMRHI). We combine our IFU data with a subsample of galaxies from the ALFALFA HI survey crossmatched to the Sloan Digital Sky Survey (SDSS) to study the FMRSFR and FMRHI across the stellar mass range 106.6–108.8 M⊙, with metallicities as low as 12 + log(O/H) = 7.67. We find the 1σ mean scatter in the MZR to be 0.05 dex. The 1σ mean scatter in the FMRSFR (0.02 dex) is significantly lower than that of the MZR. The FMRSFR is not consistent between the IFU observed galaxies and the ALFALFA/SDSS galaxies for SFRs lower than 10−2.4 M⊙ yr−1, however, this could be the result of limitations of our measurements in that regime. The lowest mean scatter (0.01 dex) is found in the FMRHI. We also find that the FMRHI is consistent between the IFU observed dwarf galaxies and the ALFALFA/SDSS crossmatched sample. We introduce the fundamental metallicity luminosity counterpart to the FMR, again characterized in terms of SFR (FMLSFR) and HI-gas mass (FMLHI). We find that the FMLHI relation is consistent between the IFU observed dwarf galaxy sample and the larger ALFALFA/SDSS sample. However, the 1σ scatter for the FMLHI relation is not improved over the FMRHI scenario. This leads us to conclude that the FMRHI is the best candidate for a physically motivated fundamental metallicity relation.