Astronomy & Astrophysics Division Seminar
Title : Advancing the Warm Calibration Unit for METIS on ELT: From Design Finalization to MAIT Phase
Date : 04-08-2025
Time : 16:00:00
Speaker : Dr. Vipin Kumar
Area : Astronomy & Astrophysics Division
Venue : 113/114, Thaltej Campus
Abstract
METIS, an advanced mid-infrared imager and spectrograph for the wavelength range 2.9-13.5 microns (astronomical L, M, and N-band), stands as one of the three science instruments at the Extremely Large Telescope (ELT). It will provide diffraction-limited imaging, coronagraphy, high-resolution integral field spectroscopy, and low and medium-resolution slit spectroscopy. Within the collaborative international METIS consortium, the University of Cologne is responsible for the design, manufacturing, and integration of the Warm Calibration Unit (WCU) of the instrument. The main role of WCU is to provide a stable and controllable reference signal to METIS that will allow troubleshooting and calibrating the response of METIS in various observing modes. In this talk, I will present the key requirements from METIS that drive the design of the WCU, followed by an overview of its optical and opto-mechanical design, and functional role within the instrument. The final part of the presentation will focus on the current status of the Manufacturing, Assembly, Integration, and Testing (MAIT) phase, including a brief discussion on the alignment verification plans for the offner relay optics of WCU.
Title : An overview of compact X-ray binaries
Date : 06-08-2025
Time : 14:30:00
Speaker : Dr. Gaurava Kumar Jaiswal
Area : Astronomy & Astrophysics Division
Venue : 113/114, Thaltej Campus
Abstract
Compact objects represent some of the most extreme environments in the universe. When these dense remnants are part of a binary system, they can draw in matter from their companion stars through a process known as accretion. This transfer of material releases vast amounts of energy, making these systems strong sources of X-rays. Compact X-ray binaries, in which a neutron star or black hole accretes matter from a companion, offer unique opportunities to study energetic processes like accretion dynamics, outbursts, and thermonuclear bursts on neutron star surfaces. This talk will introduce the fundamental concepts behind accretion, compact binaries, and related phenomena, and will highlight why these systems are key to advancing our knowledge of high-energy astrophysics.
Title : NICER insight into the High-Energy Universe
Date : 07-08-2025
Time : 16:00:00
Speaker : Dr. Gaurava Kumar Jaiswal
Area : Astronomy & Astrophysics Division
Venue : 113/114, Thaltej Campus
Abstract
Since its deployment to the International Space Station in June 2017, the Neutron Star Interior Composition Explorer (NICER) has significantly advanced our understanding of compact objects in the X-ray sky. With exceptional timing and spectral capabilities in the 0.2 - 12 keV range, NICER enables detailed studies of accretion-powered and magnetically driven phenomena. A major focus has been on thermonuclear X-ray bursts -brief, intense explosions caused by unstable burning of hydrogen and helium on neutron star surfaces, which offer key insights into the physics of dense matter. This talk will highlight crucial findings from eight years of NICER observations, covering burst behavior, accretion dynamics, X-ray transients, and magnetar activities. It will also discuss efforts to understand the interaction between compact objects and their optical companions through X-ray and optical observations. Finally, I will present recent updates on the long-term calibration of the JEM-X instruments aboard ESA's INTEGRAL mission and ongoing progress toward establishing the INTEGRAL Legacy Archive.