ICTS

In this talk, I will highlight key developments in the field of stellar archaeology, focusing on the origin of carbon enhancement and r-process enrichment in the early Galaxy. Alongside this scientific journey, my parallel role as project manager for the Hanle Echelle Spectrograph led to deeper involvement in major instrumentation initiatives such as the Thirty Meter Telescope (TMT), ultimately opening pathways into exoplanet science. I will share some of the major achievements and lessons learned from these diverse experiences. Finally, I will reflect on the advantages, challenges, and unique perspectives that come with pursuing a broad and interdisciplinary career path in astronomy.

After teaching Astronomy and Astrophysics in college for both UG/PG classes and involved with the Astro Club for the past 28 years, I noticed that the ratio of girls to boys with inclination towards the subject is similar around 50%M-50%F, at the undergraduate level. This is due to similar exposure to both the genders at an early age depending on the school and college they are studying. This ratio however does not remain the same later for Masters courses in Astronomy and Astrophysics as very few Institutions offer this subject for Masters and still very few institutions are there for PhD. Due to this many girls prefer to take Physics for their Masters as the courses are available locally in nearby Institutions (65.9%M - 34.1%F). However after Masters course it is found that many women would like to pursue their PhD in Astrophysics as scholarships are also available wherever the research institution may be located (58.3%M - 41.7%F).
I wish to discuss the above figures with facts from my own experience in college for 30 years and with actually teaching Astronomy and Astrophysics and Astro club activities for 28 years after interactions with both the genders over the years.

I will present recent insights into parsec-scale jets in Seyfert and LINER galaxies, derived from Very Long Baseline Interferometry (VLBI) observations. Despite their traditional classification as “radio-quiet,” these AGN exhibit hints of rapid jet motion, and their multi-epoch behavior reveals striking parallels with the powerful jets of radio-loud AGN. Such findings point to a continuum of jet properties across the AGN population, while also underscoring subtle but important differences between the two sub-classes. I will conclude with reflections on building and sustaining the Astronomical Society of India’s Working Group for Gender Equity (WGGE), highlighting lessons learned at the interface of science and community change.

Supermassive black holes (SMBH) that are found in the centres of most galaxies comply with scaling relationships that imply hand-in-hand growth of the SMBH and the galaxy bulge, which in turn implies that SMBHs play a significant role in regulating galaxy assembly. Our qualitative understanding is that they influence star formation via the consequences of accretion, which enables them to impact their environments out to spatial scales that are well beyond their gravitational sphere of influence, but the actual mechanisms are as yet not understood. I will describe how these mechanisms may be probed at z~0 using multi-frequency investigations, my own pathway navigating these questions and the lessons learnt while striiving to make our enterprise a welcoming one for all.

X-ray binaries, powered by accretion onto neutron stars or black holes, are among the most variable systems in the Universe. From pulsations and thermonuclear bursts to quasi-periodic oscillations, they provide unique insights into accretion physics, strong gravity, and magnetic fields. I will present recent results from AstroSat, NICER, and NuSTAR, highlighting how fast timing and broadband spectroscopy. Looking ahead, the LSST and upcoming UV missions will open new windows on compact binaries across timescales and wavelengths. I will also reflect on how the way we do astrophysics is changing. Gender inequity in physics, in general, and in astrophysics is an ongoing problem, yet initiatives like ASI’s Working Group for Gender Equity (WGGE) and CARINAS are fostering inclusivity. Just as multi-wavelength perspectives enrich science, diverse voices are vital to shaping the future of astrophysics in India.

Cosmic Noon (z ~ 2) marked a period of intense star formation for most galaxies. To understand how the baryon cycle drives disc assembly and bulge growth, I use the ERIS integral field spectrograph (IFS) to obtain high spatial and spectral resolution maps of key optical lines (H-alpha, H-beta, [O III] 5007, [N II]) in massive star-forming galaxies. Here I'll present results for ZC406690 (z = 2.19), stellar mass ~10^10.6 solar masses), a clumpy, ring-like galaxy. The three brightest clumps show asymmetric [O III] and H-alpha profiles, indicating strong stellar feedback and intense star formation. However, the emission-line ratios reveal highly ionized, dusty regions, with two brightest clumps exhibiting the highest excitation and extinction. We checked outflow measurements of the individual clumps showing moderate to extreme winds (480–>1000 km/s), with electron densities and ionization parameters varying across clumps. The dust-corrected line ratios for the clumps are consistent with photoionization models, confirming H II region-like conditions. Moreover, we also find a correlation between H-alpha/H-beta and [O III]/H-beta that suggests more dust in higher-excitation regions. Our results highlight strong, spatially variable stellar feedback shaping the physical conditions of star-forming clumps at Cosmic Noon.

At some point in the late 90s or early 00s, Indian science woke up to the fact that they have too few women. They were not wrong, but there was a problem with this framing of the problem. In this talk, I bring up anecdotes that illustrate the price science and women in STEM have to pay for the false view of equity as a women's issue.

We conducted deep radio observations of GW170817 with the Karl G. Jansky Very Large Array (VLA) at 3 GHz, targeting the field approximately 5.7 years after the binary neutron star merger. The primary objective was to search for late-time radio emission from a fast, dynamical kilonova ejecta tail and constrain theoretical models of the merger remnant. The observations comprise part of an ongoing monitoring campaign and employed standard VLA continuum imaging procedures for data calibration and analysis.
No radio emission was detected in excess of the fading jet afterglow at the source position. We determine a 3σ upper limit of 5.1 μJy at 3 GHz for the GW170817 counterpart. These stringent late-epoch results disfavor models predicting significant radio re-brightening from sub-relativistic ejecta within five to six years post-merger. Our findings provide strong constraints on the energetics and evolution of the merger remnant and inform future searches for late-time emission in similar events.