Mariangela Bernardi

Mariangela Bernardi
Standing Faculty

Associate Professor

Research Areas: Galaxies, Super-massive black holes, Observational Cosmology, Large-scale structures and peculiar motions, QSOs and Ly-alpha forest

(215) 573-6251

DRL 4N2B

Website

 

  • Associate Professor, University of Pennsylvania (2010-)
  • Assistant Professor, University of Pennsylvania (2005-2010)
  • Associate Researcher in Astrophysics, University of Pittsburgh (2004)
  • Associate Researcher in Astrophysics, Carnegie Mellon University (2002-04)
  • Associate Researcher in Astrophysics, University of Chicago (2000-02)
Education
  • Ph.D. in Astrophysics from Ludwig-Maximilians-Universitaet, Munich, Germany (1999) --  Magna cum Laude
  • Laurea from Università di Padova, Italy (1995) -- Magna cum Laude
Research Interests

Mariangela Bernardi is an Associate Professor in the Department of Physics and Astronomy at the University of Pennsylvania. Her work has focused on the analysis of galaxies properties and their environment to understand their formation and evolution, and on the co-evolution of galaxies and super-massive black holes. She has also done some work on large-scale structures, peculiar motions, QSOs and the Ly-alpha forest. Earlier on in her career she assembled, maintained and analyzed the ENEAR database used for peculiar velocity studies; it is still the only all-sky early-type galaxy database.  She demonstrated that chemical compositions of early-type galaxies in the ENEAR sample show little dependence on environment. She has been involved with the SDSS for two decades. She is acknowledged as a `Builder' of the Sloan Digital Sky Survey (SDSS). She used the SDSS to assemble and analyze what was at the time the world's largest catalog of early-type galaxies, and used it to demonstrate that velocity dispersion is the key physical parameter which determines galaxy properties. Her work showed that a shift in paradigm was needed:  minor rather than major mergers must have been an important assembly mechanism for the most massive galaxies. She also published work on the IGM and quasars at intermediate and high redshift.

More recently:
 

  • Her group produced the UPenn SDSS PhotDec Catalog of all galaxy types in the SDSS survey.  Among other things, this has led to a substantial upward revision of the world's estimate of the mass in stars in the local universe. 
  • Her group identified a new mass scale, 2 x 10^11 Msun, in the galaxy population:  above this mass, assembly by mergers matters at least as much as in-situ star formation, and the galaxy population becomes dominated by ellipticals which rotate slowly if at all.  
  • She and her group were pioneers in the use of Deep Learning techniques to estimate galaxy morphologies directly from the image pixels in galaxy surveys.  Such algorithms are necessary to turn the next generation of Big Datasets into Big Discoveries.  
  •  Her group produced two Value Added Catalogs which were included in the official SDSS-IV Data Release 15: the MaNGA PyMorph DR15 photometric catalogue and the MaNGA Morphology Deep Learning DR15 catalogue.  They used these to illustrate the power of combining reliable photometry and morphological classifications with spatially resolved spectroscopy to explore the slow- and fast-rotator dichotomy.  
  • Her group identified an important bias in Jeans-equation estimates of the masses of galaxies.  Using spatially resolved spectroscopy in the MaNGA survey, they have recently shown that accounting for stellar population gradients lowers the estimated dynamical masses, bringing them into much better agreement with those estimated from the stellar populations.  This contrasts with the consensus in the prior literature that it was the stellar population estimates which were biased.  In addition to affecting models of how and why star formation shuts off in massive galaxies, this impacts the constraints that observed galaxy velocity dispersion profiles place on modified gravity models.
  • She and her collaborators identified an important bias in currently available catalogs of super massive black holes.  Accounting for this bias resolves a number of puzzles associated with the connection between galaxy formation and black hole growth, the relation between quiescent and active galactic nuclei and their host galaxies, as well as gravity wave non-detections.

 

Courses Taught
  • Survey of the Universe
  • Intro Astrophysics I
  • Galaxies: Structure, Dynamics and Formation
Selected Publications
  • 130 published papers with a total of 26,000+ citations

  • 27 first author papers with 2700+ citations of which 10 have more than 145 citations/paper

  • 74 papers where she is one of the first three authors or the leading authors are her students/postdocs (6000+ citations)

Deep Learning for Galaxy Morphology

Transfer learning for galaxy morphology from one survey to another
Dominguez-Sanchez, H., Huertas-Company, M., Bernardi, M., Kaviraj, S., Fischer, J.-L. et al. (and 54 co-authors) 2019, MNRAS, 484, 93

SDSS-IV MaNGA PyMorph Photometric and Deep Learning Morphological Catalogues and implications for bulge properties and stellar angular momentum
Fischer, J.-L., Dominguez-Sanchez, H. & Bernardi, M. 2019, MNRAS, 483, 2057

Improving galaxy morphologies for SDSS with Deep Learning: GZOO classification scheme and T-Type catalogues 
Dominguez-Sanchez, H., Huertas-Company, M., Bernardi, M. & Fischer, J.-L. 2018, MNRAS, 476, 3661

    
MaNGA: Stellar population gradients and constraints on galaxy formation

Galaxy properties as revealed by MaNGA II. Differences in stellar populations of slow and fast rotator ellipticals and dependence on environment 
Bernardi, M., Dominguez-Sanchez, H.,  Brownstein, J. R., Drory, N. & Sheth, R. K. 2019, MNRAS, in press (arXiv:1904.11996)
 

Galaxy properties as revealed by MaNGA. I. Constraints on IMF and M*/L gradients in ellipticals 
Dominguez-Sanchez, H., Bernardi, M., Brownstein, J. R., Drory, N. & Sheth, R. K. 2019, MNRAS, in press (arXiv:1904.11992)

SDSS-IV MaNGA PyMorph Photometric and Deep Learning Morphological Catalogues and implications for bulge properties and stellar angular momentum 
Fischer, J.-L., Dominguez-Sanchez, H. & Bernardi, M. 2019, MNRAS, 483, 2057

M*/L gradients driven by IMF variation: Large impact on dynamical stellar mass estimates
Bernardi, M., Sheth, R. K., Dominguez-Sanchez, H., Fischer, J.-L., Chae, K.-H., Huertas-Company, M. & Shankar, F. 2018, MNRAS, 477, 2560

Modeling Nearly Spherical Pure-Bulge Galaxies with a Stellar Mass-to-Light Ratio Gradient under the LambdaCDM and MOND Paradigms: II. The Orbital Anisotropy of Slow Rotators within the Effective Radius 
Chae, K. H., Bernardi, M. & Sheth, R. K. 2019, ApJ, 874, 41

Modeling Nearly Spherical Pure-Bulge Galaxies with Stellar Mass-to-Light Ratio Gradient under LambdaCDM and MOND Paradigms: I. Methodology, Dynamical Stellar Mass and Fundamental Mass Plane
Chae, K. H., Bernardi, M. & Sheth, R. K. 2018, ApJ, 860, id. 81, 17


PyMorph and the UPenn SDSS PhotDec Catalog

Comparing PyMorph and SDSS photometry. II. The differences are more than semantics and are not dominated by intracluster light
Bernardi, M., Fischer, J.-L., Sheth, R. K., Meert, A., Huertas-Company, M., Shankar, F. & Vikram, V. 2017, MNRAS, 468, 2569

Comparing PyMorph and SDSS photometry. I. Background sky and model fitting effects
Fischer, J.-L., Bernardi, M. & Meert, A. 2017, MNRAS, 467, 490 

A Catalogue of Two-Dimensional Photometric Decompositions in the SDSS-DR7 Spectroscopic Main Galaxy Sample: Extension to g- and i-Bands 
Meert, A., Vikram, V. & Bernardi, M. 2016, MNRAS, 455, 2440 

A Catalogue of Two-Dimensional Photometric Decompositions in the SDSS-DR7 Spectroscopic Main Galaxy Sample: Preferred Models and Systematics
Meert, A., Vikram, V. & Bernardi, M. 2015, MNRAS, 446, 3943

Simulations of single and two-component galaxy decompositions for spectroscopically selected galaxies from the Sloan Digital Sky Survey 
Meert, A., Vikram, V. & Bernardi, M. 2013, MNRAS, 433, 1344


Distributions of galaxy observables

M*/L gradients driven by IMF variation: Large impact on dynamical stellar mass estimates 
Bernardi, M., Sheth, R. K., Dominguez-Sanchez, H., Fischer, J.-L., Chae, K.-H., Huertas-Company, M. & Shankar, F. 2018, MNRAS, 477, 2560
  
Stellar mass functions and implications for a variable IMF
Bernardi, M., Sheth, R. K., Fischer, J.-L., Meert, A., Chae, K.-H., Dominguez-Sanchez, H., Huertas-Company, M., Shankar, F. & Vikram, V. 2018, MNRAS, 475, 757

The high mass end of the stellar mass function:  Dependence on stellar population models and recent agreement on fits to the light profile
Bernardi, M., Meert, A., Sheth, R. K., Fischer, J.-L., Huertas-Company, M., Maraston, C., Shankar, F. & Vikram, V. 2017, MNRAS, 467, 2217

Mass assembly and morphological transformations since z~3 from CANDELS
Huertas-Company, M., Bernardi, M., Perez-Gonzalez, P. G., Barro, G., Daddi, E., Dimauro, P., Faber, S., Koo, D., Mei, S. & Shankar, F. 2016, MNRAS, 462, 4495

The massive end of the luminosity and stellar mass functions and clustering from CMASS to SDSS: Evidence for and against passive evolution
Bernardi, M., Meert, A., Sheth, R. K., Huertas-Company, M., Maraston, C., Shankar, F. & Vikram, V. 2016, MNRAS, 455, 4122 

The massive end of the luminosity and stellar mass functions: dependence on the fit to the light profile 
Bernardi, M., Meert, A., Sheth, R. K., Vikram, V., Huertas-Company, M., Mei, S. & Shankar, F. 2013, MNRAS, 436, 697 

Galaxy luminosities, stellar masses, sizes, velocity dispersions as a function of morphological type
Bernardi, M., Shankar, F., Hyde, J. B., Mei, S., Marulli, F. & Sheth, R. K. 2010, MNRAS, 2087

 

Joint distributions of early-type galaxy observables

Systematic effects on the size-luminosity relations of early- and late-type galaxies: dependence on model fitting and morphology
Bernardi, M., Meert, A., Vikram, V., Huertas-Company, M., Mei, S., Shankar, F. & Sheth, R. K. 2014, MNRAS, 443, 874

Evidence of major dry mergers at M* > 2 x 10^11 Msun from curvature in early-type galaxy scaling relations?
Bernardi, M., Roche, N., Shankar, F. & Sheth, R. K. 2011, MNRAS, 412, L6

Curvature in the colour-magnitude relation but not in colour-velocity dispersion: major dry mergers at M* > 2 x 10^11 Msun?
Bernardi, M., Roche, N., Shankar, F. & Sheth, R. K. 2011, MNRAS, 412, 684

The age dependence of the size-stellar mass relation and some implications
Shankar, F. & Bernardi, M. 2009, MNRAS, 396, L76

Curvature in the scaling relations of early-type galaxies
Hyde, J. B. & Bernardi, M. 2009, MNRAS, 394, 1978

Colors, magnitudes and velocity dispersions in early-type galaxies: Implications for galaxy ages and metallicities
Bernardi, M., Sheth, R. K., Nichol, R. C. et al. 2005, AJ, 129, 61

Early-type galaxies in the SDSS. II. Correlations between observables
Bernardi, M., Sheth, R. K., Annis, J. et al. 2003, AJ, 125, 1849


Super-massive black holes

  
Black hole scaling relations of active and quiescent galaxies: Addressing selection effects and constraining virial factors 
Shankar, F., Bernardi, M., Richardson, K., Marsden, C., Sheth, R. K., Allevato, V., Graziani, L., Mezcua, M., Ricci, F., Penny, S. J., La Franca, F. & Pacucci, F. 2019, MNRAS, 485, 1278
  
Selection bias in dynamically-measured supermassive black hole samples: Scaling relations and correlations between residuals in semi-analytic galaxy formation models
Barausse, E., Shankar, F., Bernardi, M., Dubois, Y. & Sheth, R. K. 2017, MNRAS, 468, 4782 

Selection bias in dynamically-measured super-massive black hole samples: dynamical masses and dependence on Sersic index
Shankar, F., Bernardi, M. & Sheth, R. K., MNRAS, 2017, 466, 4029

Selection bias in dynamically-measured super-massive black hole samples: consequences for pulsar timing arrays
Sesana, A., Shankar, F., Bernardi, M. & Sheth, R. K. 2016, MNRAS, 463, L6

Selection bias in dynamically measured supermassive black hole samples: its consequences and the questfor the most fundamental relation
Shankar, F., Bernardi, M., Sheth, R. K., Ferrarese, L., Graham, A. W., Savorgnan, G., Allevato, V., Marconi, A., Lasker, R. & Lapi, A. 2016, MNRAS, 460, 3119

Selection bias in the M_bh-sigma and M_bh-L correlations and its consequences
Bernardi, M., Sheth, R. K., Tundo, E. & Hyde, J. B. 2007, ApJ, 660, 267

On the inconsistency between the black hole mass function inferred from M_bh-sigma and M_bh-L correlations 
Tundo, E., Bernardi, M., Hyde, J. B., Sheth, R. K. & Pizzella, A. 2007, ApJ, 663, 53


Fundamental Plane

The luminosity and stellar mass Fundamental Plane of early-type galaxies
Hyde, J. B. & Bernardi, M. 2009, MNRAS, 396, 1171

Early-type galaxies in the SDSS. III. The Fundamental Plane
Bernardi, M., Sheth, R. K., Annis, J. et al. 2003, AJ, 125, 1866

 

Environmental dependence

Evolution and environment of early-type galaxies
Bernardi, M., Nichol, R. C., Sheth, R. K. et al. 2006, AJ, 131, 1288

Cluster versus Field Elliptical Galaxies and Clues on Their Formation
Bernardi, M., Renzini, A., da Costa, L. N., Wegner, G., Alonso, M. V., Pellegrini, P. S., Rité, C. & Willmer, C. N. A. 1998, ApJ Letters, 508, 143

 

Brightest Cluster Galaxies

Colour Gradients and the Colour-Magnitude Relation: Different Properties of Brightest Cluster Galaxies and E/S0 Galaxies in the Sloan Digital Sky Survey
Roche, N., Bernardi, M. & Hyde, J. B. 2010, MNRAS, 407, 1231

Evolution in the structural properties of early-type brightest cluster galaxies at small lookback time and dependence on the environment
Bernardi, M. 2009, MNRAS, 395, 1491

The luminosities, sizes and velocity dispersions of Brightest Cluster Galaxies: Implications for formation history
Bernardi, M., Hyde, J. B., Sheth, R. K., Miller, C. J. & Nichol, R. C. 2007, AJ, 133, 1741
 

BigSigs: Galaxies with the highest velocity dispersion

A search for the most massive galaxies. III. Surface brightness profiles and structural properties from HST images
Hyde, J. B., Bernardi, M., Fritz, A., Sheth, R. K. & Nichol, R. C. 2008, MNRAS, 391, 1559

A search for the most massive galaxies. II. Structure, environment and formation
Bernardi, M., Hyde, J. B., Fritz, A., Sheth, R. K., Gebhardt, K. & Nichol, R. C. 2008, MNRAS, 391, 1191

A search for the most massive galaxies: Double Trouble?
Bernardi, M., Sheth, R. K., Nichol, R. C. et al. 2006, AJ, 131, 2018
 


Peculiar velocities

Redshift-Distance Survey of Early-Type Galaxies: Dipole of the Velocity Field 
da Costa, L. N., Bernardi, M., Alonso, M. V., Wegner, G., Willmer, C. N. A., Pellegrini, P. S., Maia, M. A. G. & Zaroubi, S. 2000, ApJ Letters, 537, 81

Redshift-distance Survey of Early-type Galaxies. I. The ENEARc Cluster Sample 
Bernardi, M., Alonso, M. V., da Costa, L. N., Willmer, C. N. A., Wegner, G., Pellegrini, P. S., Rite`, C. & Maia, M. A. G. 2002, AJ, 123, 2990

 

Ly-alpha forest and He II reionization

A feature at z ~ 3.2 in the evolution of the Ly-alpha forest optical depth
Bernardi, M., Sheth, R. K., Subbarao, M. et al. 2003, AJ, 125, 32

Detection of He II reionization in the SDSS quasar sample 
Theuns, T., Bernardi, M., Frieman, J., Hewett, P., Schaye, J., Sheth, R. K. & Subbarao, M. 2002, ApJ Letters, 111, 114

CV (file)