Life and scientific activity of Mauro D'Onofrio
 
 
My past and present scientific activity covers the following research areas:
 
Extragalactic Novae, SNe and GCs;
Morphology and structure of Spiral galaxies;
Structure and kinematics of Elliptical and SO galaxies;
Double and interacting galaxies;
Galaxies in clusters at intermediate and high redshift;
Seyfert galaxies
Interferometry of Cataclismic Variables with MIDI
Rapid temporal variability with Aqueye
 
 Extragalactic Novae, SNe and GCs
 
 I started these studies when I was undergraduate student at the Department of Astronomy of the Padova University.  I earned my Laurea degree, working at the Asiago Astrophysical Observatory, with a thesis (``Study of the nova stellar system in M31'') made in collaboration with Prof. L.~Rosino and M. Capaccioli. I discovered 52 novae in the galaxy M31, appeared during the years 1971-1986. I used the photographic plates of the Asiago Observatory
Archive, and I observed the nebula with the 182cm telescope.  I studied the light curves of all the discovered novae, with a new (for that time) photometric technique, coupling the photographic material with the CCD image-device, and I derived the astrometric position of the novae within the galaxy.
 
This work resulted in 4 papers published in collaboration with L. Rosino, M. Capaccioli, and M. Della Valle.  In the first of these papers we presented the light curves of the novae. In the second we performed the largest study of the M31 nova system ever addressed, determing the frequency of outbursts, the parent stellar population of novae, and the relation between the Maximum Magnitude and the Rate of Decline (the MMRD relationship is a good distance indicator).  In the third work, we compared the M31 nova system with that of the Large Magellanic Cloud.  In the fourth paper, we derived the MMRD relation for the novae appeared in the Virgo Cluster, estimating the cluster distance and calibrating the maximum magnitude of SNe-Ia. We also gave a value for the Hubble constant H0 calibrated using the Virgo novae and the SNe-Ia. This work was done in collaboration with E. Cappellaro and M. Turatto.
 
In these years I also faced the question of the ellipticities of the M31 globular clusters (in collaboration with S. Wagner and U. Hopp at Hidelberg). We confirmed previous studies showing that the average flattening of M31 clusters is larger than those hosted in the Milky Way. The physical origin of such increase in flattening is still unknown.  We looked for correlations of the
ellipticities with the position in the parent galaxy, but we found only marginal evidences of such link.
 
Morphology and structure of spiral galaxies
 
During the PhD studies (1989-1991) I moved my research activity towards the photometry of spiral galaxies, by studying the structural components of these stellar systems. I worked with the ESO, La Palma, and Asiago telescopes.  I presented in my PhD Thesis a study of the stellar components of 80 spiral galaxies belonging to the Virgo cluster.  For each galaxy I derived the $B-V$
color and the photometric structural parameters of the bulge and disk
components, and I studied the correlations occurring among the observational parameters. In particular, I worked on the problem of the constant central surface brightness and of the internal extinction of disk galaxies.  The results of this work are published in my PhD thesis: Studies of Stellar Components in Spiral Galaxies (supervisors: Prof. M. Capaccioli and G. Ellis).
 
In collaboration with R. Rampazzo I also worked on the structure of the spiral-arms in double galaxies, using optical and near IR data obtained at the San Pedro Martir telescope in Mexico.
 
Structure and kinematics of Elliptical and SO galaxies
 
Since 1992, when I became Research Astronomer at the Department of Astronomy of the Padova University, my scientific activity progressively moved towards the study of the early-type galaxies. In collaboration with M. Capaccioli and N. Caon I published several papers concerning the photometric and dynamical properties of the hot stellar systems.  We investigated the correlations among the structural, dynamical and photometrical parameters of these galaxies.
 
A relevant study was that concerning the Kormendy relation appeared in 1992. In that paper we recognized the existence of two families of hot stellar systems, one genetic and one probably originated from the past merging activity. We also published a few papers concerning the problem of the tilt and thickness of the Fundamental Plane (FP) of early-type galaxies.  
 
A good impact work was that concerning the light profiles of early-type galaxies (it has hundreds of citations in the ADS). We demonstrated that the Sersic' law provides a better representation of the light distribution of these galaxies compared with the classical de Vaucouleurs' law.  This result is now
used by many investigators working in this research area, also from a theoretical point of view. Our analysis demonstrated that the elliptical galaxies are non-homologous structures and that the Sersic' index correlates with the tilt and the thickness of the FP.
 
In collaboration with S. Zaggia, M. Capaccioli and N. Caon, I derived
the rotation curves and the velocity dispersions of several early-type
galaxies members of the Fornax cluster.  These data, coming from the
1.54m ESO telescope, were used to study the Dn - sigma and FP relations of the Virgo and Fornax clusters, determining their relative distance.  The coefficients of the two relationships were also compared with that obtained for the Coma cluster.
 
During my visit at the Astrophysics Institute of Potsdam in 1993 (where I was visit astronomer), I established a fruitful collaboration with G. Richter for studying the faint substructures hidden in many elliptical galaxies (such as shells, ripples, small bars, inner disks, ecc.). These structures are quite frequent and are likely the final signature of a past merging activity.
My research on the Kormendy relation and the FP is still going on.
 
In the last two years I performed a 2D decomposition of the light distribution of early and late type galaxies, and applied it to 70 galaxies members of the Virgo and Fornax clusters. I discovered that the superposition of an exponential and a Sersic law produces a significantly better fit of the luminosity distribution of galaxies. I also extended the method for applications to galaxies at higher redshifts. From my analysis emerges with clarity that the nuclear and the outer parts of these galaxies cannot be fitted by the currently adopted empirical models.  For what concern the halos I have in mind the project of studying them by means of deep wide-field CCD
photometry both at the optical and near IR wavelengths. This program will be performed in collaboration with L. Secco and M. Pohlen. The properties of the halo component is today very far from being known.
An observational effort in this sense is feasible and could be achieved with the ESO telescopes. This effort would certainly give many important information on the first phases of the galaxies formation and evolution.
 
Double and interacting galaxies
 
A new fruitful collaboration started in 1998 with R. Rampazzo of the
Brera Observatory. We compared the observational parameters of several
double early-type galaxies with that of objects living in clusters and in the field. We derived the metallicity and the photometric indices of the galaxies and we addressed the problem of the age-metallicity degeneracy. We investigated the dependencies of the residuals from the FP as a function of several observational parameters, and we found strong hints of significant correlations with the Mg2 and Delta 4000 indices.
 
In the same period I studied several peculiar and interacting galaxies in collaboration with many italian astronomers. Relevant studies are that on NGC 3384, in collaboration with G. Busarello, S. Zaggia, M. Capaccioli and G. Longo, on NGC 128 in collaboration with A. Pagan, M. Capaccioli, S. Zaggia, and J. Boulesteix, and ARP 194 with P. Marziani, D. Dultzin, and J. Sulentic.  For these objects I studied the 2D light distribution and the kinematical properties (using long slit spectra taken at different telescopes).
In NGC 3384 we discovered a tilted inner bar at 90 degree from the
major axis of the galaxy.  In NGC 128 I discovered an inner counter-rotating nuclear disk, and studied the IR luminosity distribution in the JHK bands using data from the TIRGO telescope. In Arp 194 we demonstrated the interpenetrating encounter of the two galaxies, and we explained the radio emission of the observed blobs that characterize the system as due to the integrated contribution of SN remnants and radio SNe.
 
Galaxies in clusters at intermediate and high redshift
 
A few years ago I started a collaboration with G. Fasano, D. Bettoni, M. Moles and P. Kjaergaard whose aim is the study of the Kormendy relation and the FP of nearby and intermediate redshift clusters.  Up to now we published the photometric data of 7 nearby clusters. This collaboration has been enlarged including new people such as A. Sandage, W. Couch, B. Poggianti et al. producing the the survey WINGS (Wide Field Images of Nearby Galaxy Clusters Survey). The Survey has been carried out with the 2.2m telescope of La Silla and with the wide field camera of the INT telescope in La Palma. These data are today essential to address a lot of astrophysical problems, such as the universality of the FP, the structure, the number and the colors of galaxies as a function of redshift, the form of the luminosity fuction, and many other cosmological implications. Further observations in the near IR band have been planned for completing the wavelength coverage of our clusters.  The VST survey will be, of course, the natural follow-up of such work of archiving and analysis of the properties of the galaxiesin clusters.
Several papers are in preparation, presenting the results of the survey, and many have benn already published (see the list of my publications).
 
Seyfert galaxies
 
I am also working with P. Rafanelli and S. Ciroi in Padova on the spectra of Seyfert galaxies. We are determining the velocity field of many of these objects using the MPFS (Multi Pupil Fiber Spectrograph) of the SAO Observatory, in collaboration with prof. Afanasiev. The 3D MPFS spectra allow the determination of the 2D velocity field at different wavelengths in an extended region in proximity of the AGN nucleus. This data are extremely important to derive the physical properties of the gas feeding the central BH.  We are also working on the connection between the AGN activity and the
galaxy interactions.  Near IR images and spectra of these galaxies from the La Silla telescopes will be used to address several issues related to the AGN phenomenon.
With P. Marziani, D. Dultzin, and J. Sulentic I studied the close pair systems of UGC 3995, which hosts a Seyfert II nucleus, and ARP 194. The analysis of this kind of objects provides new evidences in favor of a connection between galaxy interactions and active galactic nuclei.
 
MIDI interferometry of Cataclismic Variables
 
We recently get ESO observing time with the MIDI optical interferometry, in order to study the peculiar Cataclismic Variable HD330036. We are waiting the service mode data for the next June. This project is aimed at complementing the data for the PhD thesis of our student R. Angeloni, who is working on the theoretical modeling of these kind of sources.
 
The Aqueye project
 
In the last year I was involved in the project Aqueye, by C. Barbieri and D. Dravins. The project is the first step towards the quantum astronomy. With the help of a new instrument at the focus of the 182cm telescope in Asiago, we will study the very rapid variability of astronomical sources with a time resolution of the order of few nanoseconds (an unprecedent time resolution never achived up to now).
   Born in Venice: 28/08/1961
Laurea degree in  Astronomy: 16/06/1987
Research Astronomer at the Department of Astronomy of the Padova University (Italy) since 1992
 
Professor of Complementi di Ottica Astronomica and Tecniche Astrofisiche at the Department of Astronomy of the Padova University
 
Professor of Didattica dell'Astronomia and Fondamenti di Astronomia at the SSIS: the italian school for the formation of new teachers
 
 
     MAIN HOBBIES
Mountain tracking
Skiing
Poetry
 
    Married with Simonetta
E-mail address: mauro.donofrio@unipd.it
 
Scientific activity