I am one of the three co-founders of the BASS collaboration, which is based on the least biased sample of local AGN available. As part of this multi-wavelength survey, in the past years we have created the largest existing databases of broad-band (0.3−195 keV) X-ray observations (Ricci et al. 2017d) and optical properties (Koss et al. 2017) of hard X-ray selected AGN. This allowed us to infer fundamental AGN parameters, and to double the number of heavily obscured sources in the local Universe (Ricci et al. 2015). We have currently published ∼20 papers with the BASS survey (two of which in Nature: Ricci et al. 2017c, Koss et al. 2018).
We are currently working on the second data releases, which will be part of a special issue on ApJS in early 2021. BASS provides a fundamental benchmark for studies at higher redshifts, where currently the data quality is typically lower.
I have been a member of the NuSTAR science team since 2016, and I have published several papers with the team, either as a lead-author (Ricci et al. 2016a,b; Ricci et al. 2017a,b) or as a co-author. NuSTAR is an exceptional tool to discover buried accreting supermassive black holes, and has been able to detect many AGN that were missed by previous studies. One of my main findings with NuSTAR has been the discovery that AGN in the last stages of mergers are completely enshrouded by obscuring material (see NASA press release here).
I am a member of the GATOS collaboration, which brings together AGN observers and modellers to investigate the gas flow cycle, the polar dust emission, and the torus/obscuring material properties as well as the co-evolution of the star formation activity/AGN phenomena. Much of the work of the GATOS collaboration is currently being done using ALMA observations, while we are waiting for JWST to be launched and start taking data.
GOALS combines imaging and spectroscopic data from Spitzer, Hubble, Chandra, NuSTAR and GALEX in a comprehensive study of over 200 of the most luminous infrared-selected galaxies in the local Universe. The sample consists of approximately 180 Luminous Infrared Galaxies (LIRGs), as well as over 20 Ultra-Luminous Infrared Galaxies (ULIRGs) The objects are a complete subset of the IRAS Revised Bright Galaxy Sample, and provide an unbiased picture of the processes responsible for enhanced infrared emission in the local Universe. Within the GOALS collaboration I have been leading several successful NuSTAR proposals, as well as the analysis of all the available NuSTAR observations (Ricci et al, 2017b; Ricci et al. 2021 in prep.).
The CONQUEST collaboration
Some bright IR galaxies show exceptionally luminous emission from vibrationally excited HCN. This emission comes from compact (< 15-75 pc), hot (T >100 K) and opaque (N(H2)> 1e25 cm^−2) regions centered on the nuclei, the so called Compact Nuclei (CONs). The CONQUEST collaboration was awarded ALMA data to study HCN emission in 50 objects, including 10 ULIRGs, 20 LIRGs and 20 sub-LIRGs (with IR luminosities in the 1e10-1e11 Lsun range). Within the CONQUEST collaboration I have been analyzing all the available X-ray data, to assess the activity level of the central supermassive black hole.
Credits: Aalto et al. (2015, 2019)
I am a member of SDSS-V, an all-sky, multi-epoch spectroscopic survey that will yield optical and IR spectra of over 6 million objects until 2025. In particular I am part of the Black Hole Mapper (BHM) team. BHM will target over 400,000 sources, primarily black holes, many of which will be observed numerous times, with the goal of measuring black hole masses, probing black hole growth across cosmic time, and characterizing the eROSITA X-ray sky.
Credits: M. Seibert (OCIS) & SDSS-V team
The Vera Rubin observatory will scan continuously the southern sky, detecting millions of AGN, while at the same time providing a clear look at their variability properties. LSST will also detect large numbers of extreme variability events associated to massive black holes, including tidal disruption events. I am a member of the LSST collaboration, and in particular of the AGN and Tidal disruption events working groups.
Athena is a revolutionary X-ray facility, which will allow an unprecedented look at accreting supermassive black holes in the first Gyr of life of the Universe, as well as to the circumnuclear environments of AGN, thanks to the high-resolution spectrometer. I am member of the Athena science team, and of the close environment of supermassive black holes working group.
THESEUS is a mission concept proposed to the ESA call for medium-size mission (M5), and currently in assessment phase study. The mission is designed to study high energy transient phenomena over cosmic history. I am a member of the science team, and in particular of the Time-domain Astronomy working group.
CTA is a revolutionary ground-based Gamma-ray observatory, which will allow to study the physical properties of jets in AGN, as well as energetic transient events. I am a member of the Chilean CTA collaboration.
Credits: G Perez, IAC