The COS-Holes Survey: Connecting Galaxy Black Hole Mass with the State of the CGM

Abstract

We present an analysis of \textit{HST}/COS/G160M observations of CIV in the inner circumgalactic medium (CGM) of a novel sample of eight z$\sim$0, L$\approx$L${}^{\star }$ galaxies, paired with UV-bright QSOs at impact parameters ($R_{\mathrm{proj}}$) between 25-130 kpc. The galaxies in this stellar-mass-controlled sample (log${}_{10}$M${}_{\star }$/M${}_{\odot }$ $\sim$ 10.2-10.9 M${}_{\odot }$) host super-massive black holes (SMBHs) with dynamically-measured masses spanning log${}_{10}$M${}_{\mathrm{BH}}$/M${}_{\odot }$ $\sim$ 6.8-8.4; this allows us to compare our results with models of galaxy formation where the integrated feedback history from the SMBH alters the CGM over long timescales. We find that the \ion{C}{IV} column density measurements (N${}_{\mathrm{CIV}}$) (average log${}_{10}$N${}_{\mathrm{CIV},\mathrm{CH}}$ = 13.94$\pm$0.09 cm${}^{-2}$) are largely consistent with existing measurements from other surveys of N${}_{\mathrm{CIV}}$ in the CGM (average log${}_{10}$N${}_{\mathrm{CIV},\mathrm{Lit}}$ = 13.90$\pm$0.08 cm${}^{-2}$), but do not show obvious variation as a function of the SMBH mass. In contrast, specific star-formation rate (sSFR) is highly correlated with the ionized content of the CGM. We find a large spread in sSFR for galaxies with log${}_{10}$M${}_{\mathrm{BH}}$/M${}_{\odot }$ $>$ 7.0, where the CGM \ion{C}{IV} content shows clear dependence on galaxy sSFR but not M${}_{\mathrm{BH}}$. Our results do not indicate an obvious causal link between CGM CIV and the mass of the galaxy's SMBH; however through comparisons to the EAGLE, Romulus25, $\&$ IllustrisTNG simulations, we find that our sample is likely too small to constrain such causality.

Accepted to ApJ, 28 pages, 7 figures