Summer Intern | Inter-University Centre for Astronomy and Astrophysics (IUCAA) | Jun 2023 - Jul 2023

Mentor: Mr Ashish Mhaske, Scientific and Technical Officer

  • Led a student team to measure 21-cm neutral hydrogen emission across different Galactic longitudes using a conical horn antenna.

  • Acquired spectral power measurements of the 21-cm neutral hydrogen line across Galactic longitudes, including corresponding ground and sky calibration data. After standard preprocessing, each spectrum was fitted with a Gaussian profile to determine the line-of-sight velocity corresponding to the most redshifted HI emission.

  • Derived the Milky Way rotation curve by converting the measured line-of-sight velocities to Galactocentric rotation velocities.

  • Gained hands-on experience with radiometer operation, backend electronics, and HI line fundamentals.

  • Designed and implemented a Python data-analysis pipeline to process source and calibration data.

  • In summary, measured 21-cm HI emission to derive the Milky Way rotation curve from Doppler-shifted velocities.

Results:

The plot illustrates the deviations between the theoretical rotation curve and the observed Milky Way rotation curve.

Material: