Astronomy and Coffee

Monday in Goettingen

Anyway, some work was done, identifying and remodeling objects on our last spectroscopic run, to obtain structural parameters. Some control quality will be applied tomorrow and some models will be redone, not for smaller reasons.

Also tried some wavelet modeling of a galaxy sent by Miguel Verdugo. For some weird reason the modeling stops. I'll have to look carefully why.

At late hours (at dinner time) Elif Kutdemir asked me for an object check, but everything was right with the object.

A paper worth commenting from last week. Rasmussen et al (2008, MNRAS, ..., ...). They tested the idea that hot gas in compact groups, that generates the diffuse emission, would be responsible for the HI destruction, causing the observed HI deficiency. They've got 8 HI deficient groups, did new X-ray observations, but only half their sample showed diffuse X-ray emission. So this is not the cause for the deficiency, at least not for all groups. They simulated galaxy interaction, specially ram pressure, to strip and destroy the HI. They suggest some possibilities but none really explains the deficiency.

They have an X-ray map for HCG 15, to which I have IGL analysis (Da Rocha et al, 2008), and the X-ray halo matches quite well the IGL one. Papers were published on the same issue but I was too slow to read the astro-ph version :-))

The paper, when comparing stripping of gas to stars, mentions the IGL component but misses the fact that one of their objects have detected IGL (they haven't read the paper on astro-ph) and that it was detected in HCGs before. They prefer to cite a paper in clusters, instead of something in HCG ... too bad. Sound bitter, but people that works in groups, must start reading the groups literature. They are quite different from clusters and most of the things can't be just simply scaled.

Labels: hcg, hi-z morph

posted by Cris Da Rocha @ 11:59 PM