Outputs (15)

Does the Lockstep Growth between Black Holes and Bulges Create Their Mass Relation? (2022)
Journal Article
Yang, G., Brandt, W. N., Alexander, D. M., Boquien, M., Ni, Q., Papovich, C., …Zhang, C. (2022). Does the Lockstep Growth between Black Holes and Bulges Create Their Mass Relation?. Astrophysical Journal, 940(2), Article 146. https://doi.org/10.3847/1538-4357/ac9c68

Recent studies have revealed a strong relation between the sample-averaged black hole (BH) accretion rate (BHAR) and star formation rate (SFR) among bulge-dominated galaxies—i.e., "lockstep" BH–bulge growth—in the distant universe. This relation migh... Read More about Does the Lockstep Growth between Black Holes and Bulges Create Their Mass Relation?.

The demographics of obscured AGN from X-ray spectroscopy guided by multiwavelength information (2022)
Journal Article
Laloux, B., Georgakakis, A., Andonie, C., Alexander, D. M., Ruiz, A., Rosario, D. J., Aird, J., Buchner, J., Carrera, F. J., Lapi, A., Ramos Almeida, C., Salvato, M., & Shankar, F. (2023). The demographics of obscured AGN from X-ray spectroscopy guided by multiwavelength information. Monthly Notices of the Royal Astronomical Society, 518(2), 2546-2566. https://doi.org/10.1093/mnras/stac3255

A complete census of active galactic nuclei (AGNs) is a prerequisite for understanding the growth of supermassive black holes across cosmic time. A significant challenge towards this goal is the whereabouts of heavily obscured AGN that remain uncerta... Read More about The demographics of obscured AGN from X-ray spectroscopy guided by multiwavelength information.

A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems (2022)
Journal Article
Andonie, C., Alexander, D. M., Rosario, D., Laloux, B., Georgakakis, A., Morabito, L. K., Villforth, C., Avirett-Mackenzie, M., Rivera, G. C., Del Moro, A., Fotopoulou, S., Harrison, C., Lapi, A., Petley, J., Petter, G., & Shankar, F. (2022). A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems. Monthly Notices of the Royal Astronomical Society, 517(2), 2577-2598. https://doi.org/10.1093/mnras/stac2800

To understand the active galactic nuclei (AGNs) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive mul... Read More about A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems.

Warm molecular and ionized gas kinematics in the type-2 quasar J0945+1737 (2022)
Journal Article
Speranza, G., Ramos Almeida, C., Acosta-Pulido, J., Riffel, R., Tadhunter, C., Pierce, J., Rodríguez-Ardila, A., Coloma Puga, M., Brusa, M., Musiimenta, B., Alexander, D., Lapi, A., Shankar, F., & Villforth, C. (2022). Warm molecular and ionized gas kinematics in the type-2 quasar J0945+1737. Astronomy & Astrophysics, 665, Article A55. https://doi.org/10.1051/0004-6361/202243585

We analyse Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 1045.7 erg s−1 and a... Read More about Warm molecular and ionized gas kinematics in the type-2 quasar J0945+1737.

NuSTAR Observations of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-only Scenario (2022)
Journal Article
Wang, C., Luo, B., Brandt, W., Alexander, D., Bauer, F., Gallagher, S., Huang, J., Liu, H., & Stern, D. (2022). NuSTAR Observations of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-only Scenario. Astrophysical Journal, 936(2), Article 95. https://doi.org/10.3847/1538-4357/ac886e

We utilize recent NuSTAR observations (co-added depth ≈55–120 ks) of PG 1001+054, PG 1254+047, and PHL 1811 to constrain their hard X-ray (≳5 keV) weakness and spectral shapes and thus to investigate the nature of their extreme X-ray weakness. These... Read More about NuSTAR Observations of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-only Scenario.

Localizing narrow Fe Kα emission within bright AGN (2022)
Journal Article
Andonie, C., Bauer, F. E., Carraro, R., Arévalo, P., Alexander, D. M., Brandt, W. N., Buchner, J., He, A., Koss, M. J., Ricci, C., Salinas, V., Solimano, M., Tortosa, A., & Treister, E. (2022). Localizing narrow Fe Kα emission within bright AGN. Astronomy & Astrophysics, 664, https://doi.org/10.1051/0004-6361/202142473

Context. The 6.4 keV Fe Kα emission line is a ubiquitous feature in X-ray spectra of active galactic nuclei (AGN), and its properties track the interaction between the variable primary X-ray continuum and the surrounding structure from which it arise... Read More about Localizing narrow Fe Kα emission within bright AGN.

The Black Hole Mass Function across Cosmic Time. II. Heavy Seeds and (Super)Massive Black Holes (2022)
Journal Article
Sicilia, A., Lapi, A., Boco, L., Shankar, F., Alexander, D. M., Allevato, V., Villforth, C., Massardi, M., Spera, M., Bressan, A., & Danese, L. (2022). The Black Hole Mass Function across Cosmic Time. II. Heavy Seeds and (Super)Massive Black Holes. Astrophysical Journal, 934(1), https://doi.org/10.3847/1538-4357/ac7873

This is the second paper in a series aimed at modeling the black hole (BH) mass function from the stellar to the (super)massive regime. In the present work, we focus on (super)massive BHs and provide an ab initio computation of their mass function ac... Read More about The Black Hole Mass Function across Cosmic Time. II. Heavy Seeds and (Super)Massive Black Holes.

Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars (2022)
Journal Article
Petley, J., Morabito, L., Alexander, D., Rankine, A., Fawcett, V., Rosario, D., Matthews, J., Shimwell, T., & Drabent, A. (2022). Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars. Monthly Notices of the Royal Astronomical Society, 515(4), 5159-5174. https://doi.org/10.1093/mnras/stac2067

Broad Absorption Line Quasars (BALQSOs) show strong signatures of powerful outflows, with the potential to alter the cosmic history of their host galaxies. These signatures are only seen in ∼10% of optically selected quasars, although the fraction si... Read More about Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars.

Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter (2022)
Journal Article
Fawcett, V., Alexander, D., Rosario, D., Klindt, L., Lusso, E., Morabito, L., & Calistro Rivera, G. (2022). Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter. Monthly Notices of the Royal Astronomical Society, 513(1), 1254-1274. https://doi.org/10.1093/mnras/stac945

We have recently found fundamental differences in the radio properties of red quasars when compared to typical blue quasars. In this paper, we use data from the X-shooter spectrograph on the Very Large Telescope, providing spectral coverage from ∼300... Read More about Fundamental differences in the properties of red and blue quasars: measuring the reddening and accretion properties with X-shooter.

GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching (2022)
Journal Article
Gómez-Guijarro, C., Elbaz, D., Xiao, M., Kokorev, V., Magdis, G., Magnelli, B., Daddi, E., Valentino, F., Sargent, M., Dickinson, M., Béthermin, M., Franco, M., Pope, A., Kalita, B., Ciesla, L., Demarco, R., Inami, H., Rujopakarn, W., Shu, X., Wang, T., …Treister, E. (2022). GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching. Astronomy & Astrophysics, 659, Article A196. https://doi.org/10.1051/0004-6361/202142352

Compact star formation appears to be generally common in dusty star-forming galaxies (SFGs). However, its role in the framework set by the scaling relations in galaxy evolution remains to be understood. In this work we follow up on the galaxy sample... Read More about GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching.