Astronomy and Astrophysics – Astrophysics
Scientific paper
Nov 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993a%26a...279...61n&link_type=abstract
Astronomy and Astrophysics (ISSN 0004-6361), vol. 279, no. 1, p. 61-74
Astronomy and Astrophysics
Astrophysics
39
Absorption Spectra, Cooling Flows (Astrophysics), Cosmic Dust, Emission Spectra, Interacting Galaxies, Interstellar Extinction, Interstellar Gas, Ionized Gases, Line Spectra, Star Clusters, Astronomical Photometry, Charge Coupled Devices, H Ii Regions, Luminosity
Scientific paper
Our CCD images reveal that some of the well-known absorption features in NGC 1275 do not show up in the distribution of the low velocity (LV) ionized gas. The absorption features have the same asymmetrical distribution around the nucleus as the high velocity (HV) emission line system. The extinction of the features is significantly different from the Galactic law. Our analysis shows that the dust responsible for the extinction is most probably well within NGC 1275. Altogether, we argue that most of the absorption features are associated with the HV system, implying that the HV system has moved halfway through NGC 1275. We have found many more objects than recently discovered by Hubble Space Telescope (HST)(Holtzman et al. 1992). We have been able to define three groups of objects with distinct differences in distribution around the nucleus: (1) a group of mainly giant H II regions, nearly all associated with the HV system, (2) old globular clusters in a total number of about 2/3 of the number of globular clusters in M87 (assuming a universal luminosity function of globular clusters), and (3) an intermediate group (IG), of both extended and point sources, with 0.0 less than or equal to (V-I)0 less than or equal to 0.75. The IG is peaking strongly at the nucleus of NGC 1275, with a smooth and symmetrical distribution. For the extended IG objects, we estimate an age less than or equal to 107 yr, while the point sources could have ages 107 to 109 yr. We suggest that the IG objects have been formed in a cooling catastrophe, set up in the central part of the extended X-ray emitting gas of the Perseus Cluster. Very little (except for the giant H II regions) excess light in our V frame can be associated with the HV system. We find -16.1 greater than or equal to MV(HV) greater than or equal to -17.3, implying that the HV system is extremely luminous in hydrogen alpha compared to the visual luminosity.
Goudfrooij Paul
Hansen Leif
Jorgensen Henning E.
Norgaard-Nielsen Hans Ulrik
No associations
LandOfFree
The extinction and star clusters in NGC 1275 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 The extinction and star clusters in NGC 1275, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The extinction and star clusters in NGC 1275 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-807285