Sayak’s Title: Probing the circumgalactic medium of low redshift galaxies

Abstract: The circumgalactic medium (CGM) retains imprints of the physical processes that drive galaxy evolution, encoded in its physical conditions and chemical composition. Quasar absorption line spectroscopy offers a sensitive means of probing this tenuous medium; however, it requires a statistically significant sample of quasar-galaxy pairs to effectively map the CGM. In this talk, I will discuss efforts to map the CGM traced by neutral hydrogen (H I) and highly ionized oxygen (O VI) with a core sample using MUSEQuBES (MUSE Quasar-Field Blind Emitters Survey) at low redshift (z<1) complemented by archival observations. Finally, I will briefly discuss efforts to map the CGM in emission using integral-field spectroscopy with MUSE, highlighting one serendipitous discovery.

Prasad’s Title: Optical Frequency Comb Enabled Time–Frequency Characterization of Entangled Ultrafast Biphotons

Abstract: Optical frequency combs are specialized laser sources that act like a ruler for light enable applications from atomic clocks to exoplanet searches. We harness their precisely controlled pulses for ultrafast quantum state characterization. Direct measurements of biphotons remain challenging because single-photon detectors lack femtosecond resolution and conventional pump-probe methods require long acquisition times. Using 93 fs Yb comb pulses for frequency-upconversion optical sampling, we achieve sub-100 fs timing resolution and reconstruct a 1.42 ps cross-correlation of picowatt Er comb pulses. The method rapidly measures biphoton joint temporal and spectral intensities simultaneously, enabling study of ultra fast time-frequency quantum correlations.