Contact

Address


Dr. Manash Samal, Room 213, Astronmy & Astrophysics Divison,
Physical Research Laboratory, Ahmedabad 380009, Gugarat, India
Phone:+91-79-26314613

Email


[email protected], [email protected]



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Welcome

I am a faculty at the Physical Research Laboratory (PRL), seeking answers to some fundamental questions such as how and where do stars or cluster of stars form in the Universe, and how these stars influence the interstellar medium and regulate the star formation processes of the host Galaxy.

I look to the above problems with astronomical observations using ground and space observatories in a huge range of wavelengths. In particular, I use telescopes observing in the radio, millimeter, infrared, and optical domain to get information about the stars, and the gas and dust associated to them. You can find more details on my work on my research page and all my publications can be found on my publication page.


Recent Results

 How are dense regions of our Galaxy converting gas into stars? Is star formation efficiency per free-fall time truly universal?
In a recent analysis of 17 nearby parsec-scale, cluster-forming clumps of our Galaxy, we estimated the star formation efficiency (SFE), star formation rate (SFR), and also examined the clump-scale star-formation scaling laws. We found a median instantaneous SFE of ~20% and an SFE per free-fall time (εff) of ~13% for the clumps. The εff values are found to be notably higher than the commonly assumed universal value. We discuss the scaling laws and suggests that εff may not be universal across all scales but instead varies with local conditions and physical processes. For details see Rawat et al. 2025.
Posted June 10th, 2025
Figure showing variation of luminosity ratio of HCN and HCO+ with metallicity
Variation of Dense Gas Mass-Luminosity conversion factor with metallicity in the Milky Way
In a recent study, we investigated the effect of metallicity on the mass-luminosity conversion factor derived from HCN and HCO+, which are commonly used tracers of dense gas. Our analysis revealed substantial variation in the abundance ratio of these tracers with metallicity, as well as across the galactocentric radius. We discuss the implications of these results in gas mass estimation and its potential role in explaining the observed low star formation efficiency in the central molecular zone of our Galaxy. For details see Patra et al. 2024, arXiv:2503.07931
Posted March 19th, 2025