Calculating star formation rate (SFR) of ~100 galaxies [article]

Harisah Mehmood, University Of Calgary, University Of Calgary, Jeroen Stil
The size of the galaxy aperture was taken from the optical images of the galaxies from NED database (see Fig. 5 .). Growth curve showed optical size was too small, see Fig. 4a . SOLUTION: Changed the Galaxy aperture to 2X the optical size (see Fig. 4b ). Helpful for blurred & invisible galaxies too. 2--Turned on software inherent background subtraction on some images ISSUE: Growth curve for some galaxies exhibited a rising trend past the galaxy size, see Fig. 6a . SOLUTION: Turn on background
more » ... btraction in Fig. 6b . 3--Removing nearby stars falling into the Galaxy aperture ISSUE: Nearby stars falsely contribute to the Galaxy flux, see Fig. 7a. SOLUTION: Wrote a python program to remove the unwanted stars, see Fig. 7b. 4--Calculating UV flux error by devising a new test ISSUE: The flux error calculated by the program was based on photon statistics. This method overlooks the presence of sky background structure. SOLUTION: Devised a test where flux from four non--star regions of every galaxy was calculated. Then the standard deviation of the fluxes of one galaxy was then plotted against the respective galaxy size. See results in Fig. 8a, 8b.
doi:10.11575/prism/10456 fatcat:w5fckmn6szdfxpvtc2jcphbnpa