PROGETTI PER TESI DI DOTTORATO - PHD PROJECTS
Questa è la lista di alcune delle possibili tesi di dottorato. I supervisori possono essere contattati per ulteriori informazioni
This is the list of the possible Ph.D. projects proposed by the Doctoral School of Astronomy of Padua University. The supervisors can be contacted for further information.
SOLAR SYSTEM AND EXTRA-SOLAR PLANETS
SEARCH FOR EXTRASOLAR PLANETS (3 Phd thesis offered)
G. Piotto
The search and characterization of extrasolar planets is a new,fascinating research field in Astronomy.
Padova is the largest center in Italy for extrasolar planet Astronomy.We have ongoing an observational program for the detection of planets using the TTV and TDV method Holman (2005 Science, 307, 1288). A huge number of nights at Asiago, Teide and La Palma, as well as CTIO and La Silla telescopes have been assigned for forthcoming months. This data set, and additional, similar observations can become the basis a PhD thesis project.
A PhD thesis on TTV/TDV search of exoplanets is offered.
We have also a key role (both scientific and techonological) in the development of PLATO (PLAnetary Transits and stellar Oscillations) project, a space mission approved by the European Space Agency within the Cosmic Vision program, and aimed at the search for terrestial planets in habital zones with the photometric transit techinique (satellite launch foreseen for 2018).
Prof. Giampaolo Piotto is responsible of the Italian contribution to PLATO, and of the related science activities in Italy. Roberto Ragazzoni (of the nearby Astronomical Observatory) is the responsible of the optical design and the building of PLATO telescopes.
A PhD thesis on the science exploitment of PLATO is offered.
In addition, next spring, HARPS-N (https://plone2.unige.ch/HARPS-N) will start operations at the Italian 3.5m telescope TNG. HARPS-N will be the best northern emisphere instrument for the search of exoplanets with radial velocity method; 400 guarantee time nights have been reserved for next 5 years for the follow-up of Kepler candidate exoplanets. Prof. Piotto is member of the international Science Team which will exploit this huge amount of observational time.
A PhD thesis based on HARPS-N data is offered.
The activity of the research group of Prof. Piotto is complemented by the collaboration with researchers at the nearby Astronomical Observatory, where there is a group actively involved in the search for extrasolar planets with the radial velocity technique. The same group has a relevant role in the construction of instruments with VLT and the forthcoming ELT for the direct observations of planets .
.
STARS
SUPERNOVAE AS PROBES FOR THE LATE STAGES OF THE EVOLUTION OF MASSIVE STARS AND THE CHEMICAL EVOLUTION OF THE UNIVERSE
S. Benetti
The determination of the chemical enrichment by the different types of supernovae and on the study of the extremes of the SN population are keys questions in modern astrophysics. Indeed the standard assumptions in galaxy evolution models, i.e. 0.6Msun of Fe from SNIa, 0.1Msun of Fe (plus O/Ca/Mg) from SNII, are far from being reasonable approximations. There are evidences that the ejected Fe mass ranges from 0.1 to 1.0Msun for SNIa, and from 0.002 to 0.4Msun for core collapse SNe, occasionally reaching about 1Msun in SNIb/c. The amounts of other elements are even more variable (and largely unknown). The comparison of optical and IR observations with theoretical models, developed by our group, will permit to derive the chemical abundances and stratification of the expanding ejecta. This, together with the SN rates and their evolution with redshift, will establish the contribution of SNe to the cosmic chemical evolution. The second goal is to extract invaluable physical parameters also from the study of extreme (in terms of luminosity, progenitor mass and/or mass loss, explosion mechanisms, etc..) objects. This project is closely related to the ESO-NTT and TNG large programs (in the framework of a large international collaboration lead by B. Benetti) which are starting on October 2009 and will last 4 years. To these projects about 140 of observing nights have been awarded. Depending on the attitude and interests of the student, the PhD thesis can focus on observations, data analysis or modelling.
THE VISTA SURVEY OF THE MAGELLANIC CLOUD SYSTEM
L. Girardi
The VMC survey will map the entire Magellanic Clouds in the VISTA Y,J,Ks passbands and down to the oldest turn-off, allowing us to determine the spatially-resolved star formation history (SFH) with unprecedented quality and to construct a detailed 3D map of the system. The primary scope of the PhD project is in the realisation of artificial star tests and SFH-recovery tests, using both simulated data and the first VMC images to be available in 2008. This is to be followed by the analysis of the RGB and AGB populations.
ON THE PROGENITORS OF TYPE Ia SUPERNOVAE
L. Greggio
The aim of the work is to investigate on the nature of the progenitors of Type Ia Supenovae using both empirical evidences and theoretical arguments. In particular, the observed rates in different stellar populations can be used to constrain the distribution function of the delay times and the realization probability of the SNIa event. The comparison of these two quantities to the predictions of the single and binary stellar evolution theory leads to conclusions on the nature of SNIa progenitors.
CALIBRATING MODELS OF ASYMPTOTIC GIANT BRANCH STARS WITH HST DATA
P. Marigo
L. Girardi
AGB stars contribute a large fraction of the light emitted from galaxies,
especially in the near-infrared, and even in optical wavelengths for young
galaxies observed at high redshifts. Calibrating stellar models of the AGB
is therefore of utmost importance for studies of galaxy formation and
evolution. This calibration is now possible using the combined photometry
of several millions of resolved stars in galaxies up to distances of 4
Mpc, coming from two HST surveys: the ACS Nearby Galaxy Survey
Treasury in the optical, and a snapshot survey that will soon start using
the new WFC3 camera in the near infrared.
The PhD project consists in modelling such data using the most up-to-date
models of stellar evolution. Close interaction with the Seattle group led
by J. Dalcanton is foreseen.
PHYSICS AND EVOLUTION OF CLASSICAL NOVAE, DURING THEIR OUTBURSTS AND QUIESCENCE
U. Munari
R. Barbon
We are monitoring (high and low resolution spectroscopy; UBVRI photometry) all novae erupting in the last few years (with Asiago, TNG and ESO telescopes as well as several robotic ones in both emispheres). We study the evolution of their outburst, their expanding ejecta, derive the chemical abundances and compare with expectation from theory of thermonuclear runaways, search the archives for the progenitor, and follow the object during its return to quiescence, investigating in particular the super-soft phase and the mechanism of irradiation of the donor star by the outbursting companion.
The project is carried out in collaboration with an international team.
ECLIPSING BINARIES PROBING FINEST DETAILS OF THEORETICAL STELLAR MODELS
U. Munari
R. Barbon
From high resolution spectroscopic observations and photoeletric/CCD photometry accurate orbits of double lines, eclipsing binaries are derived, and detailed atmospheric analysis (in particular chemical abundances) is carried out. Resulting masses, radii, temperatures, luminosities, metallicities accurate to better than 1 percent are used to constrain in details the predictions of current theoretical stellar models.
RED CLUMP STARS AS TRACERS OF GALACTIC STELLAR DYNAMICS
U. Munari
R. Barbon
The absolute magnitude of high galactic latitude red clump stars is calibrated as function of temperature, gravity, metallicity derived from high resolution spectroscopy. Multi-epoch radial velocities and proper motions, are then used to compute galactic orbits and to investigate the dynamics and chemical history of our galaxy, including remnants of mergers.
SCIENCE FROM THE RAVE SPECTROSCOPIC SURVEY OF THE SOUTHERN HEMISPHERE
U. Munari
R. Barbon
The RAVE survey has so far accumulated high quality digital spectra, radial velocities and atmospheric parameters of more than 200,000 high galactic latitude southern stars. Many different science applications of this huge collection of state-of-the-art stellar spectra data are possible and offered to the interested applicant.
THE POPULATION OF X-RAY BINARIES IN THE LOCAL GROUP
M. Orio
The students who would like to work on this project will spend part of their three years (1-2 years) at the University of Wisconsin in Madison, USA and the rest of the time at the Observatory of INAF-Padova. A large population of X-ray binaries has been discovered and partly studied in M31, M33, M32 and the small satellites of M31 and the Milky Way. These discoveries mark the beginning of a new era in the studies of close binaries with compact objects. Using X-ray, UV, near IR and optical observations we will characterize this still mostly mysterious population of "extreme" objects. Specific topics on which a thesis may focus include:
- The evolution of type Ia supernovae progenitors,
- The primordial X-ray binaries of dwarf spheroidal galaxies,
- Black hole transients in M31,
- The nova rate and nova classes in Local Group galaxies.
We will use X-ray telescopes such as those on board XMM-Newton, Chandra and Swift, UV telescopes (Galex and Swift), the WIYN, SALT, ESO and CTIO (and possibly other) medium and large size ground based telescopes.
The period at the University of Wisconsin will be fully funded on available research grants.
MULTIPLE STELLAR POPULATIONS IN STAR CLUSTERS
G. Piotto
The recent discovery (by our group) of multiple evolutionary sequences in galactic globular clusters has seriously challenged the paradigm of star clusters hosting a simple stellar population, formed at the same epoch, from the same material. These new findings may have vast implications on star formation processes, and on population synthesis models used to interpret the light from galaxies at cosmological distances. This is a lively debated argument in the present astronomical literature. The PhD student will be inserted in an international collaboration (of which the group in Padova is the leader) and work on the analysis of data from: 1) already approved Hubble Space Telescope programs (which include both ongoing observations and programs approved for observations in 2011 with the new cameras mounted onboard HST), and 2) approved ESO/VLT programs both with wide field imagers and high resolution spectrographs. The PhD student will gain an expertise on high precision photometry and astrometry on HST data and/or on the exploitation of high resolution spectroscopic data. The possibility of formation stages at ESO, Space Telescope Science Institute, and other European and USA Universities is offered.
COMPACT OBJECTS AND THEIR EXPLOSIVE ORIGIN (A)
L. Zampieri
The research in the area of Relativistic Astrophysics carried out at the Astronomical Observatory of Padua is centered on the investigation of the physics of compact objects, in particular neutron stars and black holes, and their explosive origin. The focus is on the observational analysis and theoretical modelling of the powerful phenomena that originate in accretion flows onto compact objects, in particular in Galactic and extra-galactic X-ray binary systems, and in the explosive events that end the life of massive stars, namely supernovae in different environments. The proposed project consists in the development of a radiation hydrodynamics numerical code to compute the light curve and photospheric emission properties of the ejecta of a supernova starting from realistic post-explosion configurations. The code will be interfaced with other existing tools (a pre-supernova evolution and explosion code and a spectral synthesis code) to build a 'Core-Collapse Supernova Laboratory'. Model-data comparison to infer the energy of the explosion and the physical parameters of the exploding star and the compact remnant is also expected to be carried out.
COMPACT OBJECTS AND THEIR EXPLOSIVE ORIGIN (B)
L. Zampieri
The research in the area of Relativistic Astrophysics carried out at the Astronomical Observatory of Padua is centered on the investigation of the physics of compact objects, in particular neutron stars and black holes, and their explosive origin. The focus is on the observational analysis and theoretical modeling of the powerful phenomena that originate in accretion flows onto compact objects, in particular in Galactic and extra-galactic X-ray binary systems, and in the explosive events that end the life of massive stars, namely supernovae in different environments. The proposed project consists in the observational analysis and theoretical modeling of the physical properties of a particularly interesting class of objects, the ultraluminous X-ray sources, that are believed to host very massive black holes whose origin is still unclear.
|top|
GALAXIES AND COSMOLOGY
THE EVENTFUL LIFE OF GALAXIES IN LOW DENSITY ENVIRONMENTS: A MULTI-WAVELENGHT APPROACH
R.Rampazzo
Interaction, accretion and merging events along the Hubble time play a key role in determining the overall galaxies properties. Several studies suggest that such events are well effective not only in clusters but also in the poor galaxy aggregates of low density environments (LDE). Provided that typical galaxy aggregates in LDE, such as groups, today contain a substantial fraction of the mass of the Universe, this implies that the local environment strongly affects the evolution of most galaxies.
In this context very poor galaxy aggregates and nearly isolated galaxies, in particular early-type galaxies (ETGs) deserve a special value. The former class includes the simplest systems where the effect of the ongoing interaction on the galaxy evolution can be directly tested, while ETGs are widely considered the fossil evidence of the process of galaxy evolution. We adopt the so called archeological approach, i.e the subject of our investigations are nearby objects, where multi-wavelength studies of single galaxies, of the groups structure and of the inter-galactic medium (IGM) can be performed with an unprecedented detail exploiting the new generation of telescopes and instruments.
The thesis will make use of proprietary and archival data sets and will be developed within national and international collaborations.
More details about the project in http://web.oapd.inaf.it/rampazzo/
DARK ENERGY UNVEILED BY TYPE Ia SUPERNOVAE
R. Barbon
S. Benetti
E. Cappellaro
M. Turatto
L. Zampieri
After their contribution to the discovery of the acceleration of the Universe, Supernovae of Type Ia are expected to play a major role to unveil the nature of the mysterious dark energy. The success of the new experiments, planning the detection of thousands of distant SN Ia, requires that the precision of SN Ia as distance indicators improves down to a few percents. Combining new, high quality observations and improved tools for the modeling of the light curve and spectra we aim to give to the new generation of experiments (e.g. JDEM, DUNE, which are just being planned within large international collaborations) the necessary theoretical ground for using the SNIa as standardized candles to unveal the nature of the dark energy. These space experiments will, in fact, characterize, the dark energy density, equation of state, and time variation by precisely and accurately measuring the distance-redshift relation of Type Ia supernovae.
SUPERMASSIVE BLACK HOLES AND THEIR HOST GALAXIES
F. Bertola
E.M. Corsini
E. Dalla Bonta`
L. Morelli
A. Pizzella
Recent years have seen dramatic progress in the study of the nuclear properties of galaxies. It resulted that masses of supermassive black holes are tightly related to large-scale properties of their host spheroids. This suggests that the formation and evolution of galaxies and supermassive black holes are closely entwined. During the PhD program dynamical measurements of the masses of supermassive black holes will be performed with state-of the-art observations and models. The project will be developed within an international collaboration involving the Oxford University, Max-Planck-Institut fuer extraterrestrische Physik in Munich, Space Telescope Science Institute in Baltimore, and Hezberg Institute in Victoria.
DARK MATTER IN GALAXIES
F. Bertola
E.M. Corsini
E. Dalla Bonta`
L. Morelli
A. Pizzella
A big effort has been spent in the last years to verify whether the radial density distribution of dark matter in galaxies is characterized by either a central cusp or a constant density core. Disentangling between these two extreme cases has relevant cosmological implications. We are working on this subject following complementary approaches by measuring the dark matter content and distribution in low surface brightness galaxies by means of stellar kinematics and in barred galaxies from their bar pattern speed. The study is carried out in view of the next lunch of GLAST, the Gamma Large Area Space Telescope aimed at unveiling the nature of the dark matter particles. The project will be developed within an international collaboration involving the Oxford University, Instituto de Astrofisica de Canarias in Tenerife, and University of Washington in Seattle.
GALAXY METALLICITY AS A FUNCTION OF REDSHIFT
F. Bertola
E.M. Corsini
E. Dalla Bonta`
L. Morelli
A. Pizzella
The metallicity as a function of redshift is tightly linked to the star formation history of the universe. Metallicity can be estimated in faint objects by measuring the [OII], [OIII] and Hbeta line strength. The PhD student will have access to VLT/VIMOS spectra of a sample of objects at redshift z=0.4. The project will be developed within an international collaboration involving the Space Telescope Science Institute in Baltimore.
THE RELATION BETWEEN CIRCULAR VELOCITY AND VELOCITY DISPERSION IN GALAXIES
F. Bertola
E.M. Corsini
E. Dalla Bonta`
L. Morelli
A. Pizzella
Recently, it has been pointed out that the asymptotic circular velocity of disk and central velocity dispersion of the spheroid in high surface brightness galaxies are tightly related. This relationship is valid for galaxies of all the different morphological types, ranging from ellipticals to spirals. It has direct implications for galaxy formation models, linking the central supermassive black hole, to bothe the bulge and dark matter halo. During the PhD program the student will analyze photometric and spectroscopic data obtained with the Very Large Telescope for a sample of low surface brightness galaxies. These galaxies seems to show either higher circular velocity or lower velocity dispersion with respect to the high surface brightness counterparts. This will allow to test the relevance of baryon collapse to the radial density profile of the dark matter halos of low surface brightness galaxies.
THE DENSE MOLECULAR GAS IN NEARBY BARRED GALAXIES
D. Bettoni
G. Galletta
In order to understand the global distribution of dense molecular medium in galaxies, we plan to conduct an extragalactic CO(3-2) imaging survey of nearby barred spiral galaxies. The CO(3-2) line emission, in submillimeter wavelenghts, is a good tracer of dense gas because its Einstein A coefficient is proportional to nu^3 ; therefore, the critical density of CO(3-2) emission is higher than that of CO(1-0) by a factor of < 33 , i.e., n< 10e4 cm-3.
This survey will be focussed on a sample of nearby barred galaxies selected among those where CO(1-0) emission has been detected. The sample will be composed both by normal barred galaxies (from the catalogue of Bettoni et al 2003) and by barred interacting galaxies (from the catalogue of Casasola et al 2004) in order to understand if the presence of a dense interstellar medium may be influenced by the environmental conditions. In particular we will study the characteristics in the bar region of the dense molecular medium that could be driven to the central region and, undergoing to a strong shock, may be a huge reservoir to "fuel" future starbursts in the central regions. The program will apply for millimetric observations with the 30m telescope of Pico Veleta (for the northern emisphere) and with APEX (for the southern one).
In collaboration with V. Casasola (INAF-Firenze).
VIRIALIZATION OF DENSITY PERTURBATIONS IN QCDM COSMOLOGIES. THE QUINTESSENCE EQUATION OF STATE, THE QUINTESSENCE DEGREE OF CLUSTERING, AND THE RELATED SCALAR POTENTIAL, SHALL FOLLOW DIFFERENT PRESCRIPTIONS.
R. Caimmi
APPLICATION OF THE TENSOR VIRIAL THEOREM TO A GENERAL CLASS OF (COLLISIONAL AND COLLISIONLESS) FLUIDS, AIMED TO A DESCRIPTION OF GALAXIES AND CLUSTER OF GALAXIES.
R. Caimmi
MODELS OF CHEMICAL EVOLUTION WITH INSTANTANEOUS RECYCLING ASSUMED BUT INSTANTANEOUS MIXING RELAXED, AND COMPARISON WITH OBSERVED METALLICITY (OXYGEN) DISTRIBUTIONS IN THE GALAXY AND/OR M31.
R. Caimmi
MULTIFREQUENCY PROPERTIES OF QUASARS
P. Marziani
P. Mazzei
The doctoral project is focused on the interpretation of optical/UV/NIR/FIR spectral properties of quasars, with the main aim to connect measured parameters to physical properties like central black hole mass, spin, bolometric luminosity, and Eddington ratio. The work will be based on a statistical and physical analysis of high-quality spectral datasets collected over the years by our group. This includes VLT proprietary observations, HST, SDSS archival spectra, as well of FIR/submillimeter data. A perspective doctoral student will measure optical and UV emission lines, interpret them in the framework of theoretical models, and carry out an analysis of the spectral energy distribution to isolate any thermal (host galaxy) contribution to the quasar luminosity. The student will be part of a major collaboration involving researchers in Italy, USA, and Mexico, as well as 2 senior graduate students.
PROPERTIES OF GALAXIES IN NEARBY CLUSTERS
M. D'Onofrio
T. Valentinuzzi
Proposers: the WINGS (Wide-field Imaging of Nearby Galaxies cluster Survey) project team. Research data: (i) clusters images taken with the UKIRT NIR camera and LBT optical camera in the U band; (ii) medium resolution spectra of cluster galaxies. Research program: Using the photometric (UBVJK) and spectroscopic data for several thousands galaxies of the WINGS survey, the PhD student will study the properties of galaxies in nearby clusters, with particular attention in the galaxy structure/morphology and stellar population. The aim is to trace the history of the galactic transformations using the galaxies in nearby clusters as a local cosmic rule.
THE HERSCHEL SPACE MISSION
A. Franceschini
The Herschel Space Observatory is the most important ESA mission of the decade (launch summer 2008) and a unique opportunity for european astronomers. The thesis advisor, co-investigator of the mission, is involved in a wide effort of exploiting Herschel for the exploration of the distant universe. The thesis will consider various aspects of such cosmological investigations, including modellistic work of IR galaxy evolution, interpretation of Herschel data and even data analyses, according to the preferences of the perspective student.
COSMOS, SWIRE, AND SPITZER COSMOLOGICAL SURVEYS
A. Franceschini
The team proposing the thesis is actively involved in wide international collaborations dedicated to the exploitation of the most advanced instrumentation for cosmological investigations in the darkest sky regions. The forefront of these is the COSMOS project over a 2 sq.deg. field, including HST ACS data; SWIRE is a wide-area (49 sq.deg.) with Spitzer IR data. The thesis will consider the effects of environment on the formation and evolution of cosmic structures (galaxies and AGNs in particular).
TEV ASTRONOMY, THE PROBLEM OF COSMIC OPACITY AT TEV PHOTON ENERGIES, AND THE COSMIC IR BACKGROUND
A. Franceschini
Observations of very high energy (TeV) photons are now routinely possible with Tcherenkov telescopes. The team proposing the thesis collaborates with collegues of the Physics Department involved in the MAGIC consortium. The thesis will concern the important question of the cosmological opacity of the universe to TeV photons due to their interaction with those of the cosmic optical and IR backgrounds (photon-photon collisions). The topic will not only address all the phsical problems related with this phenomenon, but also will exploit TeV observations of BLAZARs over a wide redshift range to constrain the intensity of the extragalactic radiations and compare them with direct determinations and their modellistic interpretation.
VIOLENT RELAXATION MECHANISM OF A STELLAR SYSTEM INSIDE THE GRAVITATIONAL POTENTIAL OF A DARK MATTER HALO: THEORIES, MODELS, SIMULATIONS
L. Secco
THE ROLE OF CLAUSIUS' VIRIAL ENERGY MAXIMIZATION IN THE FEATURES OF THE GALAXY FUNDAMENTAL PLANE AND ITS INTERFACE WITH COSMOLOGY AND THERMODYNAMICS
L. Secco
EFFECTS OF THE GALACTIC TIDES AND STELLAR MASS ON OORT CLOUD DYNAMICS
L. Secco
ELLIPSOIDAL COLLAPSE IN DARK MATTER HALOES
G. Tormen
In this project a set of N-body numerical simulation is used to test the predictions of ellipsoidal collapse of dark matter haloes regarding the timing of collapse, shape of final haloes, and correlation between initial and final properties.
L'origine e l'evoluzione del legame tra la massa delle galassie e il loro ambiente: simulazioni e osservazioni
G. Tormen, B. Poggianti
Nell'ambito dello studio della formazione ed evoluzione delle galassie, il progetto di tesi combina teoria e osservazioni. L'obiettivo scientifico è quello di investigare come e perchè, a diverse epoche cosmologiche, la funzione di massa delle galassie cambia con l'ambiente in cui esse si trovano, per poter distinguere i processi fisici che governano l'evoluzione delle galassie stesse. Il progetto utilizzerà simulazioni numeriche, modelli e osservazioni che rappresentano lo stato dell'arte a livello internazionale. Il programma si svilupperà su tre linee: l'analisi della più grande simulazione numerica cosmologica di materia oscura, l'utilizzo dei dati osservativi per la determinazione delle masse galattiche e la caratterizzazione del loro ambiente, e infine il confronto tra teoria e osservazioni. Il progetto si svolgerà in collaborazione tra il Dipartimento di Astronomia dell'Università di Padova e due Osservatori Astronomici (Padova e Trieste) dell'Istituto Nazionale di Astrofisica, e prevede un periodo di formazione negli Stati Uniti.
|top|
