López Iván
Italy – Università di Bologna – INAF/OAS
A black hole’s gotta eat too: accretion on low-luminosity AGN
Spectral Energy Distribution (SED) fitting is a popular technique to derive properties of galaxies, such as stellar masses and Star Formation Rate (SFR), and from their active nuclei, such as bolometric Luminosities produced by the central black hole’s accretion. We used the code Cigale on an X-ray-selected sample of active galaxies until z<2.5 with data from X-ray to mid-IR and obtained reliable values of the accretion luminosity. We compared these properties to understand how they affect the host galaxy’s global properties in the co-evolution scenario. Now, we are applying a similar methodology with a nearby sample of galaxies (<50Mpc, based on the Palomar sample), extending the multiwavelength data to far-IR and radio. In this sample, we can focus our SED fitting in the inner part of the galaxy, obtaining better constraints on their accretion luminosities, torus properties, and star-forming regions in the inner parsec.
We will present a new module for Cigale designed especially for low-luminosity AGN that helps us to recover the black hole properties even for radiatively inefficient accretion disks (like Advection-dominated accretion flow (ADAF) or regular truncated disk). We can understand the Eddington rate distribution and Black Hole mass function in the local Universe by combining this sample with high-luminosity ones, like BASS.
We also studied some sources of this sample to understand all the details of AGN Feedback in action. For one in particular, we will show Spitzer IRS spectral maps that reveal spectacular, extended H2 emission from warm (200-300 K) molecular gas in the inner 2.5 kpc of the spiral galaxy M58 (NGC4579). Gemini NIRI imaging of the H2 1-0 S(1) emission line and archival ALMA CO 2-1 and HST multiband imaging show that most of the H2 emission corresponds to lanes of dusty molecular gas that spiral towards the galaxy nucleus, where the PAH emission is consistent with excitation by UV radiation from old stars in the galaxy bulge rather than star formation. The most plausible scenario is that the inner radio jet is shock-heating the kpc-scale molecular disk. Jet-shocked H2 may impact star formation and help regulate the masses of the stellar bulges and SMBH in otherwise normal spiral galaxies. In the future, JWST will observe this galaxy (Cycle 2, PI: Lopez, IE) to resolve spatially and kinematically the jet-ISM interactions at a scale of 10 pc and determine what fraction of the molecular and ionized gas is heated in place and what fraction is an outflow. JWST will also yield the molecular and ionized gas outflow rates, which we will compare to the SMBH accretion and nuclear star formation rates to determine how important these processes are in regulating both.