School description > Research projects
The students will be separated in groups of four to five, and assigned to a research project under the supervision of an expert tutor. A total of 50 hours will be available to work on the projects.
The projects will be carried-on using the students own laptops (and access to remote servers when necessary), that shall ideally be running a Linux-like environment. Prescriptions concerning the software packages to be pre-installed will be communicated before the school.
The list of projects is below:
- Stellar Spectral Classification and Interpolation
Tutors: Ranjan Gupta (IUCAA, Pune) & Harinder P Singh (University of Delhi, New Delhi)
Description: The Project will involve Artificial Neural Network (ANN) based classification tools for two dimensional classification (Spectral Type and Luminosity) of stellar spectral libraries. The 1D spectra (ascii files) will be provided to the project group.
Software requirements: The participants shall keep Python/Matlab based open source ANN classification tools ready for performing the project on their laptops (preferably on LINUX or MAC; use the Matlab license of your home institute or university).
- Kinematics of galaxies at z=1 with outflows or inflows.
Tutor: Nicolas Bouché (CRAL, Lyon)
Description: The goal of this project is to apply 3D methods to derive galaxy kinematics of distant galaxies at z=1 with known outflows or inflows. We will extract kinematics from MUSE observations and investigate the angular-momentum of these galaxies and compare to larger samples.
Software requirements: It will be based on the python-based GalPak3D algorithm which fits parametric 3D model to galaxies. We can also potentially compare the results with the 3DBarrollo non-parametric algorithm. The project participant should test the installation of these libraries on their laptop ahead of the beginning of the project.
Extension: Implement the non-parametric (Gaussian Processes with pymc3)
- Determination of stellar atmospheric parameters of globular cluster stars from MUSE observations
Tutor: Philippe Prugniel (CRAL, Lyon)
Description: We will derive the atmospheric parameters of stars from the globular cluster NGC6397, using spectra extracted from MUSE cubes as described in Husser et al. (2016). We will compare with the resuls obtained by the former paper, and by Jain et al. (2020). MUSE started the era of crowded-fields spectroscopy, where the whole field of a star cluster can be observed at once, to be then decomposed into individual spectra. In this way, the complete population can be observed, down to some flux limit. A star cluster is an ideal place to check the stellar evolution models, and to benchmark the different approaches foreseen to evaluate the chemical composition and physical parameters of stars.
Software requirements: FERRE (a F90 code), and whatever scripting language, like Python, GDL or IDL (for figures and to prepare the data)
- Modelling a Lyman continuum leaker at z=0.99 from AstroSat
Tutor: Kanak Saha (IUCAA, Pune)
Description: Lyman continuum (LyC) leakers are the objects from which photons with wavelength shorter than 912 angstrom are able to escape their host. What fration of these photons escape the host remains unclear. Not only that, depending on the redshift (in particular from high z), many of these photons get absorbed by the intervening intergaactic medium (IGM) on their way to Earth. However, the second problem is comparatively less severe for low-z galaxies. Analog of these low-z galaxies might have played a crucial role during the Cosmic reionization of our universe. The primary goal of this project is to model a relatively low-z galaxy at z=0.99 and estimate the escape fraction of the LyC photons.
Data: (a) Far and Near-Ultra-Violet imaging data (unpublished) from UVIT/AstroSat will be provided.
(b) Archival data from HST, VLT and Spitzer (downloadable) .
(c) Spectroscopic data from MUSE and HST grism.
Objectives: (i) Construct a spectral energy distribution of the z=0.99 galaxy.
(ii) Model the SED using PCIGALE/BPASS.
(iii) Derive physical parameters: stellar mass, Z, dust.
(iV) Estimate escape fraction.
Tools/Software: Good knowledge of photometry: PSF, daophot, aperture photometry. Python with astropy, numpy, scipy. Install Pcigale with anaconda env. Candidates with knowledge of spectral analysis will be a plus.
- Is there a massive black hole in the globular cluster NGC 6388?
Tutor: Sebastian Kamann (LJMU, UK)
Description: It is a long-standing question whether some globular clusters harbour massive black holes in their centres. Such objects, frequently called intermediate-mass black holes (IMBHs), would be the smaller siblings of the supermassive black holes commonly found in the centres of massive galaxies. Their presence could suggest that some globular clusters are in fact the remnants of former galaxies that were accreted by the Milky Way.
However, finding IMBHs is challenging, as numerous velocity measurements of stars in the very centres of the clusters are required. Until today, there is no globular cluster where the presence of an IMBH has been provde beyond reasonable doubt. The case of the massive Galatic globular cluster NGC 6388 is particularly controversial. Using integral-field spectroscopy, different research groups have either argued for the presence of an IMBH as massive as 12000 solar masses, or ruled out the presence of any object more massive than 2000 solar masses. In this research project, the students will use unpublished MUSE narrow-field mode data to study the central kinematics of NGC6388 and t solve the controversy of its putative massive black hole.
Literature:
(1) Review on intermediate-mass black holes: Greene et al. (2019)
(2) The status of IMBH seaches in the Milky Way: Baumgardt (2017)
(3, 4, 5) Studies searching for an IMBH in NGC 6388: Luetzgendorf et al. (2011), Lanzoni et al. (2013), Luetzgendorf et al. (2015)
(6) Using MUSE to search for intermediate-mass black holes: Kamann et al. (2016)
Data availability:
(1) The reduced MUSE data cube will be made available prior to the start of the school.
(2) HST-Photometry of the stars in NGC 6388 is available from the HUGS survey
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