Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-09-06
Astronomy and Astrophysics
Astrophysics
To appear in ApJ Letters; 12 pages, 4 figures
Scientific paper
10.1086/324313
We have used the Wisconsin H-Alpha Mapper (WHAM) to observe the spatially extended distribution of ionized hydrogen in M31 beyond the stellar disk. We obtained five sets of observations, centered near the photometric major axis of M31, that extend from the center of the galaxy to just off the edge of the southwestern HI disk. Beyond the bright stellar disk, but within the HI disk, weak H-alpha is detected with an intensity I(H-alpha) = 0.05 (+0.01 / -0.02) Rayleighs. Since M31 is inclined 77 degrees with respect to the line of sight, this implies that the ambient intergalactic ionizing flux onto each side of M31 is Phi_0 <= 1.6 x 10^4 photons cm^-2 s^-1. Just beyond the outer boundary of the HI disk we find no significant detection of H-alpha and place an upper limit I(H-alpha) <= 0.019 Rayleighs.
Haffner Matthew L.
Madsen Greg J.
Maloney Philip R.
Reynolds Ron J.
Tufte Stephen Louis
No associations
LandOfFree
Observations of the Extended Distribution of Ionized Hydrogen in the Plane of M31 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 Observations of the Extended Distribution of Ionized Hydrogen in the Plane of M31, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations of the Extended Distribution of Ionized Hydrogen in the Plane of M31 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-384293