Seminars / Webinars
Wednesday 20 July 2022, 13:00 (EET)
Star Formation Quenching in L* Ellipticals
Suraj Dhiwar
Inter-University Centre for Astronomy and Astrophysics, Pune, India
Abstract:
In this talk, I will present our study on star formation quenching in L* ellipticals. We have studied the evolution of L* elliptical galaxies in the color-magnitude diagram in terms of their star-formation history and environment in an attempt to learn about their quenching process. For this, from a parent sample of 36500 galaxies that were spectroscopically selected from Stripe82 of the Sloan Digital Sky Survey, we have selected a sample of 12 blue-cloud L* ellipticals (BLE), 11 green-valley L* ellipticals (GLE), and 28 red-sequence L* ellipticals (RLE) based on visual inspection and their surface-brightness profiles. Our analysis shows that most of the RLEs and GLEs are quenched only recently or are still forming stars, based on their [OIII] and Hα emission, while the BLEs are forming stars vigorously. Further, the star-formation in BLEs is found to be extended over the galaxy and not confined to their central region. The galaxy color correlates with the cosmic-web environment, with the BLEs tending to reside in lower-density regions, the RLEs preferring denser, clustered regions, and the GLEs found in either region. I will discuss the possible scenarios that cause this migration of the star-forming ellipticals towards the red sequence.
I will also give a short introduction of my ongoing projects on emission line mapping and UV morphology of intermediate redshift star-forming galaxies, and Lyman Continuum (LyC) emitters at redshift 1.0 < z < 2.0, which is being carried out using the deep imaging data from Ultra-Violet Imaging Telescope (UVIT) on board Astrosat.
Past webinar recordings are available here
Past Webinars
| Date | Speaker | Title |
| 18 Jul 2022 | Samik Mitra Prime Minister's Research Scholar, Department of Physics, IIT Guwahati, India |
Properties of general relativistic magneto-hydrodynamics accretion flows around black holes in steady-state limit (Watch here) |
| 12 Jul 2022 | Christos Efthymiopoulos University of Padova, Department of Mathematics |
The information approach to the interpretation of quantum mechanics (Watch here) |
| 5 Jul 2022 | Kanak Saha Inter-University Centre for Astronomy and Astrophysics, Pune, India |
Growth and survival of bars in disk galaxies (Watch here) |
| 28 Jun 2022 | Georgios Loukes-Gerakopoulos Astronomical Institute of the CAS, Czech Republic |
Celestial Mechanics of Extreme Mass Ratio Inspirals (Watch here) |
| 14 Jun 2022 | Matthaios Katsanikas Research Center for Astronomy and Applied Mathematics, Academy of Athens |
Stickiness in 3D rotating galactic potentials (Watch here) |
| 9 Jun 2022 | Makrina Agaoglou Instituto de Ciencias Matematicas, Madrid, Spain |
Transport processes on a Potential Energy Surface with four wells, four index-1 saddles and an index-2 saddle (Watch here) |
| 24 May 2022 | Susanna Parenti Institut d'Astrophysique Spatiale, France |
Validation of a wave heated 3D MHD coronal-wind model using Polarized Brightness and EUV observations (Watch here) |
| 17 May 2022 | Konstantina Zouloumi Research Center for Astronomy & Applied Mathematics & Department of Astrophysics, Astronomy and Mechanics, University of Athens |
NAAF determination of the multiple pattern speeds and the manifolds in a simulation of a barred spiral galaxy (Watch here) |
| 3 May 2022 | Antonios Tsokaros University of Illinois at Urbana-Champaign, USA |
Numerical general relativity and astrophysics in the era of multimessenger astronomy (Watch here) |
| 18 Apr 2022 | Stavros Pastras Research Center for Astronomy and Applied Mathematics, Academy of Athens & Department of Physics, Section of Astrophysics, Astronomy and Mechanics, University of Athens |
Gasflows in barred spiral galaxies by means of two different hydrocodes (Watch here) |
| 12 Apr 2022 | Spyridon Aleiferis UK Atomic Energy Authority, Culham Science Centre, Abingdon, UK |
Taming of the stars: how to control fusion plasmas (Watch here) |
| 31 Mar 2022 | Evangelos Melas University of Athens, Department of Economics |
Asymptotic symmetries and representation theory in General Relativity in three and four space-time dimensions (Watch here) |
| 29 Mar 2022 | Georgios Doulis Institute of Theoretical Physics, University of Jena, Germany |
Entropy as shock indicator in neutron star merger simulations (Watch here) |
| 15 Mar 2022 | Dimitris Stamatellos Jeremiah Horrocks Institute for Mathematics, Physics & Astronomy, University of Central Lancashire, Preston, UK |
The formation and evolution of disc-instability planets (Watch here) |
| 10 Mar 2022 | Damianos Iosifidis Aristotle University of Thessaloniki |
Perfect Hyperfluids (Watch here) |
| 8 Mar 2022 | Antonios Nathanail University of Athens, Department of Physics |
Still observing light from the binary neutron star merger first detected in 2017 (Watch here) |
| 3 Mar 2022 | Karnesis Nikolaos Aristotle University of Thessaloniki, School of Physics |
Detecting Gravitational Waves from space (Watch here) |
| 22 Feb 2022 | Athanasios C. Tzemos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Chaos and Bohmian Quantum Potential (Watch here) |
| 15 Feb 2022 | Ioannis Contopoulos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Quantum Interference: reality or an illusion of the detector? (Watch here) |
| 8 Feb 2022 | Charis Anastopoulos Department of Physics, University of Patras |
Gravitational effects in macroscopic quantum systems (Watch here) |
| 1 Feb 2022 | Konstantinos N. Gourgouliatos Department of Physics, University of Patras |
Magnetic Field Evolution in Neutron Star Crusts: Hall effect and beyond ( Watch here) |
| 18 Jan 2022 | Athanasios C. Tzemos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Born's rule in the case of 3 entangled Bohmian qubits (Watch here) |
| 11 Jan 2022 | Constantinos Kalapotharakos University of Maryland and Astrophysics Science Division, NASA/Goddard Space Flight Center, USA |
Interpreting the Thermal and Non-Thermal High-Energy Emission in Multipolar Field Pulsar Magnetospheres (Watch here) |
| 14 Dec 2021 | Thorsten Naab Max-Planck-Institute for Astrophysics, Garching, Germany |
The GRIFFIN project - towards realistic simulations of galactic star cluster populations (Watch here) |
| 7 Dec 2021 | Ivan Minchev Leibniz-Institut für Astrophysik Potsdam (AIP) |
Modeling the Galactic disk in the age of Gaia (Watch here) |
| 30 Nov 2021 | Edoardo Legnaro Research Center for Astronomy and Applied Mathematics of the Academy of Athens and University of Thessaloniki |
Analytic Theory for Secular Lunisolar Resonances (Watch here) |
| 9 Nov 2021 | Dimitri A. Gadotti ESO – European Southern Observatory |
Nuclear discs in external galaxies and the Milky Way: building "bulges" without mergers (Watch here) |
| 26 Oct 2021 | Demosthenes Kazanas NASA Goddard Space Flight Center, Corresponding Member of the Academy of Athens |
Gravity beyond Einstein? Yes, but in which direction? (Watch here) |
| 13 Jul 2021 | Dimitris Christodoulou University of Massachusetts |
Major-Body Clustering in the Solar System (Watch here) |
| 24 Jun 2021 | Panos A. Patsis Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Building blocks of 3D, X-shaped bulges and thick spirals (Watch here) |
| 8 Jun 2021 | George Contopoulos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Μια συνοπτική έκθεση της Φιλοσοφίας της Φυσικής και των Μαθηματικών (Διαθέσιμη μαγνητοσκοπημένη) |
| 1 Jun 2021 | Christos Efthymiopoulos Department of Mathematics Tullio Levi-Civita, University of Padua (Work in collaboration with Rita Mastroianni) |
Secular dynamics for exoplanetary systems with two planets in mutually inclined orbits (Watch here) |
| 13 May 2021 | Athanasios C. Tzemos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Born's Rule in the case of two entangled Bohmian qubits
(Watch here) |
| 22 Apr 2021 | Costis Gontikakis Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Study of the emission measure during a solar flare observed with IRIS spectrograph (Watch here) |
Seminars in 2020
| Date | Speaker | Title |
| 3 Mar 2020 | Anastasios Anastasiadis National Observatory of Athens / IAASARS |
Unveiling Current Challenges in Space Weather Forecasting: The SAWS-ASPECS tool |
| 25 Feb 2020 | Vasileios Basios Université Libre de Bruxelles, Interdisciplinary Centre for Nonlinear Phenomena & Complex Systems (Cenoli-ULB) & Département de Physique des Systèmes Complexes et Mécanique Statistique |
Labyrinth Chaos: Conservative, non-Hamiltonian Chaos without Attractors |
| 18 Feb 2020 | Elias Koulouridis National Observatory of Athens / IAASARS |
Tracing the Universe: X-ray surveys and cosmology |
| 11 Feb 2020 | Costis Gontikakis Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Moss, the trace of hot loops in EUV, an ongoing research |
| 28 Jan 2020 | Athanassios C. Tzemos Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Chaos and ergodicity in the trajectories of two entangled Bohmian qubits |
| 21 Jan 2020 | George Dimopoulos National Observatory of Athens |
Coronal properties of Sy I Active Galaxies |
| 14 Jan 2020 | Panos A. Patsis Research Center for Astronomy and Applied Mathematics of the Academy of Athens |
Some open issues in Galactic Dynamics and the contribution of Image Processing in resolving them |
A list of all previous seminars from 2008 to 2020 is available here.
