Abstract Details
| Name: Bhaswati Affiliation: NCRA Conference ID: ASI2018_1635 Title : Searching for pulsars with GMRT : Fermi-directed search and GHRSS survey Authors and Co-Authors : Jayanta Roy (NCRA) Abstract Type : Contributed Talk Abstract Category : Stars,ISM and the Galaxy Abstract : Even though pulsars are frequently getting discovered with ongoing surveys at major telescopes over the world, presently known population is only 1% of prediction. Because of the generally steep spectral nature of pulsars, lower frequencies are an obvious choice for searching for fainter pulsars away from the Galactic plane, where search sensitivity is not severely affected by sky temperature and increased scattering. Pulsar surveys with the GMRT are benefited by its huge collecting area, low frequency coverage and high resolution backends. In this presentation, I will detail on discovery of 21 pulsars using the Giant Metrewave Radio Telescope (GMRT) from targeted (Fermi directed search) and blind surveys (GMRT High Resolution Southern Sky - GHRSS) and results from the follow up studies. With the aid of reduced quantised noise and high time-frequency resolution supported by the GMRT software backend, search sensitivity of GMRT was improved significantly resulting in discovery of 8 millisecond pulsars in Fermi-directed searches, which are the first Galactic millisecond pulsars discovered with the GMRT. The GHRSS survey is an off-Galactic-plane (|b| >5) survey at 322 MHz with complementary target sky (declination range −40 deg to −54 deg) to other ongoing low-frequency surveys by GBT and LOFAR. With ~60% of the survey completed (i.e. 1800 deg^2), we discovered of 13 pulsars, survey including one MSP, one pulsar with LAT pulsation and two mildly recycled pulsars. This is one of the highest pulsar per square degree discovery rate for any off-Galactic plane survey. The simultaneous time-domain and imaging study for localising pulsars and transients and efficient candidate investigation with machine learning are some of the features of the GHRSS survey, which are also finding application in the SKA design methodology. Recently we have embarked on the second phase of the GHRSS survey using the upgraded GMRT at 300-500 MHz. |