Yogesh Maan
Reader-F
Email: ymaan [at] ncra.tifr.res.in
Phone: 02025719277
Extn: 9277
Office: F231
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Savitribai Phule Pune University Campus,
Pune 411 007
Maharashtra, INDIA
Tata Institute of Fundamental Research
Savitribai Phule Pune University Campus,
Pune 411 007
Maharashtra, INDIA
Main Research Areas: Radio Pulsars, Magnetars, Compact Objects: Searches for pulsars, fast radio bursts, and other transients; Data analysis techniques and algorithm development; Radio astronomy instrumentation.
Biography:
Yogesh Maan obtained his B.Sc. from Govt. College Jind, Kurukshetra University, and his M.Sc. from Panjab University. He then joined the Joint Astronomy Programme (JAP) run by the Indian Institute of Science, Bangalore, for his Ph.D. Under this programme, he moved to the Raman Research Institute in 2006 and finished his doctoral research on observational studies of radio emission from pulsars, including very low frequency probes of a large number of gamma-ray pulsars in 2013. After postdoctoral positions at National Centre for Radio Astrophysics (NCRA; 2014-16) and ASTRON, The Netherlands (2016-20, 2020-21), he moved back to NCRA as a faculty member in July 2021.Research description:
My broad research interest is to understand various observational aspects of the radio emission from pulsars, magnetars and other compact objects, and those of fast radio bursts (FRBs). Currently, my research work primarily focuses on: (1) Radio emission from Magnetars and their inter-connection with pulsars and FRBs, (2) Targeted searches for pulsars and FRBs, and (3) Development of signal processing techniques.
Magnetars
The emission from magnetars is believed to be driven by the magnetic energy, as against the rotation power for the radio pulsar population. The radio emission from magnetars is particularly intriguing as it exhibits remarkable levels of similarities as well as dissimilarities with that from the radio pulsars. Several theoretical models of FRBs also advocate magnetars as potential sources of FRBs. However, unlike radio pulsars, the radio emission from magnetars is transient in the sense that they emit in radio wavelengths for relatively short durations, often following a high-energy outburst. Using sensitive telescopes, such as GMRT, GBT, and earlier the Arecibo telescope, we catch these enigmatic objects in their radio-active phases, to understand the underlying radio emission mechanism and its link with that in radio pulsars, and any inter-connection with FRBs.
The emission from magnetars is believed to be driven by the magnetic energy, as against the rotation power for the radio pulsar population. The radio emission from magnetars is particularly intriguing as it exhibits remarkable levels of similarities as well as dissimilarities with that from the radio pulsars. Several theoretical models of FRBs also advocate magnetars as potential sources of FRBs. However, unlike radio pulsars, the radio emission from magnetars is transient in the sense that they emit in radio wavelengths for relatively short durations, often following a high-energy outburst. Using sensitive telescopes, such as GMRT, GBT, and earlier the Arecibo telescope, we catch these enigmatic objects in their radio-active phases, to understand the underlying radio emission mechanism and its link with that in radio pulsars, and any inter-connection with FRBs.
Targeted searches for pulsars and fast transients
Targeted searches utilize the already available information to pre-select the sky areas, or sometimes even sources, towards which the probability of finding pulsars or fast transients is high. One such example is the population of compact, steep spectrum radio sources, a big fraction of which has been uncovered by the recent imaging surveys. By conducting time-domain as well as interferometric radio observations of these steep spectrum sources at a number of frequencies (300 MHz to 5 GHz), using a number of sensitive telescopes (GMRT, ORT, Arecibo, European VLBI Network), we are trying to answer the questions like: (1) what fraction of the steep spectrum population is comprised of pulsars? (2) are these pulsars fundamentally different from the other conventionally detectable pulsars? (3) how fruitful such approaches of searching for new pulsars would be in the SKA era?
Targeted searches utilize the already available information to pre-select the sky areas, or sometimes even sources, towards which the probability of finding pulsars or fast transients is high. One such example is the population of compact, steep spectrum radio sources, a big fraction of which has been uncovered by the recent imaging surveys. By conducting time-domain as well as interferometric radio observations of these steep spectrum sources at a number of frequencies (300 MHz to 5 GHz), using a number of sensitive telescopes (GMRT, ORT, Arecibo, European VLBI Network), we are trying to answer the questions like: (1) what fraction of the steep spectrum population is comprised of pulsars? (2) are these pulsars fundamentally different from the other conventionally detectable pulsars? (3) how fruitful such approaches of searching for new pulsars would be in the SKA era?
Signal processing techniques
Developing new algorithms and techniques is a necessity in today's age of data-driven, observational science. In a recently concluded exercise, we developed a new method and software RFIClean (see https://github.com/ymaan4/RFIClean) to efficiently excise radio frequency interference (RFI) contamination, and retain most of the useful time-domain data even in the presence of severe RFI. In an ongoing development, I am devising a faster way to search for FRBs by using an optimum way of dedispersing data simultaneously at multiple DMs.
Developing new algorithms and techniques is a necessity in today's age of data-driven, observational science. In a recently concluded exercise, we developed a new method and software RFIClean (see https://github.com/ymaan4/RFIClean) to efficiently excise radio frequency interference (RFI) contamination, and retain most of the useful time-domain data even in the presence of severe RFI. In an ongoing development, I am devising a faster way to search for FRBs by using an optimum way of dedispersing data simultaneously at multiple DMs.
Selected publications:
(1) Chromatic periodic activity down to 120 MHz in a Fast Radio Burst (I. Pastor-Marazuela, L. Connor, J. van Leeuwen, Y. Maan, et al., 2021, Nature, 596, 505) (2) Fourier domain excision of periodic radio frequency interference (Y. Maan, J. van Leeuwen, & D. Vohl, 2021, A&A, 650, A80). (3) Repeating fast radio bursts with WSRT/Apertif (L. C. Oostrum, Y. Maan, J. van Leeuwen, et al., 2020, A&A, 635, A61). (4) Distinct Properties of the Radio Burst Emission from the Magnetar XTE J1810-197 (Y. Maan, B. C. Joshi, M. P. Surnis, et al., 2019, ApJL, 882, L9). (5) A Search for Pulsars in Steep Spectrum Radio Sources (Y. Maan, C. Bassa, J. van Leeuwen, et al., 2018, ApJ, 864, 16). (6) Discovery of Low DM Fast Radio Transients: Geminga Pulsar Caught in the Act (Y. Maan, 2015, ApJ, 815, 126). (7) Deep searches for decametre-wavelength pulsed emission from radio-quiet gamma-ray pulsars (Y. Maan & H. A. Aswathappa, 2014, MNRAS, 445, 3221). (8) RRI-GBT Multi-band Receiver: Motivation, Design, and Development (Y. Maan, A. A. Deshpande, V. Chandrashekar, et al., 2013, ApJS, 204, 12).
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