%0 Generic %1 joshi2017nebular %A Joshi, Ravi %A Srianand, Raghunathan %A Petitjean, Patrick %A Noterdaeme, Pasquier %D 2017 %K MgII [OII] emission low-z %T O II nebular emission from Mg II absorbers: Star formation associated with the absorbing gas %U http://arxiv.org/abs/1706.03075 %X We present nebular emission associated with 198 strong Mg II absorbers at 0.35 $z łe$ 1.1 in the fibre spectra of quasars from the Sloan Digital Sky Survey. Measured O II luminosities (L$_O II$) are typical of sub-L$^\star$ galaxies with derived star formation rate (uncorrected for fibre losses and dust reddening) in the range of 0.5-20 $M_ødot\ yr^-1$. Typically less than $\sim$ 3% of the Mg II systems with rest equivalent width, $W_2796$ $\ge$ 2 \AA, show L$_O II 0.3$ L$^\star_O II$. The detection rate is found to increase with increasing $W_2796$ and $z$. No significant correlation is found between $W_2796$ and L$_O II$ even when we restrict the samples to narrow $z$-ranges. A strong correlation is seen between L$_O II$ and $z$. While this is expected from the luminosity evolution of galaxies, we show finite fibre size plays a very crucial role in this correlation. The measured nebular line ratios (like O III/O II and O III/H$\beta$) and their $z$ evolution are consistent with those of galaxies detected in deep surveys. Based on the median stacked spectra, we infer the average metallicity (log Z $\sim$8.3), ionization parameter (log $q$ $\sim$7.5) and stellar mass (log (M/M$_ødot$)$\sim$9.3). The Mg II systems with nebular emission typically have $W_2796$ $2$ \AA, Mg II doublet ratio close to 1 and W(Fe II$łambda$2600)/$W_2796$ $0.5$ as often seen in damped Ly$\alpha$ and 21-cm absorbers at these redshifts. This is the biggest reported sample of O II emission from Mg II absorbers at low impact parameters ideally suited for probing various feedback processes at play in $z1$ galaxies.

@misc{joshi2017nebular, abstract = {We present nebular emission associated with 198 strong Mg II absorbers at 0.35 $\le z \le$ 1.1 in the fibre spectra of quasars from the Sloan Digital Sky Survey. Measured [O II] luminosities (L$_{[O II]}$) are typical of sub-L$^{\star}$ galaxies with derived star formation rate (uncorrected for fibre losses and dust reddening) in the range of 0.5-20 ${\rm M_\odot\ yr^{-1}}$. Typically less than $\sim$ 3% of the Mg II systems with rest equivalent width, $W_{2796}$ $\ge$ 2 \AA, show L$_{[O II]} \ge 0.3$ L$^{\star}_{[O II]}$. The detection rate is found to increase with increasing $W_{2796}$ and $z$. No significant correlation is found between $W_{2796}$ and L$_{[O II]}$ even when we restrict the samples to narrow $z$-ranges. A strong correlation is seen between L$_{[O II]}$ and $z$. While this is expected from the luminosity evolution of galaxies, we show finite fibre size plays a very crucial role in this correlation. The measured nebular line ratios (like [O III]/[O II] and [O III]/H$\beta$) and their $z$ evolution are consistent with those of galaxies detected in deep surveys. Based on the median stacked spectra, we infer the average metallicity (log Z $\sim$8.3), ionization parameter (log $q$ $\sim$7.5) and stellar mass (log (M/M$_\odot$)$\sim$9.3). The Mg II systems with nebular emission typically have $W_{2796}$ $\ge 2$ \AA, Mg II doublet ratio close to 1 and W(Fe II$\lambda$2600)/$W_{2796}$ $\sim 0.5$ as often seen in damped Ly$\alpha$ and 21-cm absorbers at these redshifts. This is the biggest reported sample of [O II] emission from Mg II absorbers at low impact parameters ideally suited for probing various feedback processes at play in $z\le 1$ galaxies.}, added-at = {2017-06-13T10:04:02.000+0200}, author = {Joshi, Ravi and Srianand, Raghunathan and Petitjean, Patrick and Noterdaeme, Pasquier}, biburl = {https://www.bibsonomy.org/bibtex/2a7895c49ce8daa66e4a9e58d102a55d6/miki}, description = {[1706.03075] [O II] nebular emission from Mg II absorbers: Star formation associated with the absorbing gas}, interhash = {c961e3af08b0323c2bb63e60f1ca42b1}, intrahash = {a7895c49ce8daa66e4a9e58d102a55d6}, keywords = {MgII [OII] emission low-z}, note = {cite arxiv:1706.03075Comment: 18 Pages, 18 Figures, 4 Tables (Accepted for the Publication in MNRAS main-journal)}, timestamp = {2017-06-13T10:04:02.000+0200}, title = {[O II] nebular emission from Mg II absorbers: Star formation associated with the absorbing gas}, url = {http://arxiv.org/abs/1706.03075}, year = 2017 }