Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-08-14
Astron.J.122:3017-3045,2001
Astronomy and Astrophysics
Astrophysics
to appear in Astronomical Journal (Nov. 2001) tarfile includes: main text (61 pages), 24 figures (jpeg format), 4 tables
Scientific paper
10.1086/323445
(first paragraph) We have obtained Halpha and Palpha emission line images covering the central 3 - 4 arcmin of M51 using the WFPC2 and NICMOS cameras on HST to study the high-mass stellar population. The 0.1 - 0.2 arcsec pixels provide 4.6 - 9 pc resolution in M51 and the Halpha/Palpha line ratios are used to obtain extinction estimates. A sample of 1373 Halpha emission regions is catalogued using an automated and uniform measurement algorithm. Their sizes are typically 10 - 100 pc. The luminosity function for the Halpha emission regions is obtained over the range L_{Halpha} = 10^{36} to 2 times 10^{39} erg s{-1}. The luminosity function is fit well by a power law with dN/dlnL proportional to L^{-1.01}). The power law is significantly truncated and no regions were found with observed L_{Halpha} above 2 times 10^{39} erg s^{-1} (uncorrected for extinction; the maximum seen in ground-based studies is approximately a factor of 5 higher, very likely due to blending of multiple regions). The extinctions derived here increase the maximum intrinsic luminosity to above 10^{40} erg s^{-1}). The logarithmically binned luminosity function is also somewhat steeper (alpha = -1.01) than that found ground-based imaging (alpha = -0.5 to -0.8) - probably also a result of our resolving regions which were blended in the ground-based images. The 2-point correlation function for the HII regions exhibits strong clustering on scales <= 2 arcsec or 96 pc.
Ewald Shawn
Polletta Mari
Rieke Marcia
Scoville Nicholas Z.
Stolovy Susan Renee
No associations
LandOfFree
High Mass, OB Star Formation in M51 : HST Halpha and Palpha Imaging does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with High Mass, OB Star Formation in M51 : HST Halpha and Palpha Imaging, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High Mass, OB Star Formation in M51 : HST Halpha and Palpha Imaging will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-135708