Apparent Brightness

• Hopkins et al.
• http://arxiv.org/abs/astro-ph/0204528
• star-formation rates of 50 well known, local Blue Compact Dwarf (BCD) galaxies based on their 1.4 GHz and 60 $\mu$m luminosities
• Mk600, SBS0335-052, IZw18, UM461, UM462, Mk930

• Dowell et al.
• http://arxiv.org/abs/astro-ph/0611586
• SSCs in nearby spirals and irregulars from SDSS
• SDSS colors plus spectral evolutionary modelling to determine cluster ages and mass.
• They find a steeper slope for the mass function (at high masses) in irregulars as compared to spirals.
• I wonder how reliable the masses are from this method. It’s a tricky business and dynamical cluster masses would be nicer.

Things that happen when you neglect your blog #187: You find a finished article that you forgot to publish and which is quite outdated now. You now have to bite the bullet and publish it anyway, because you are to cheap to ditch it.

“You” in that case is, of course, me. So here it comes:

It has already been all over the news and blogs, but I cannot resist to comment a little more on the newly opened Galaxy Zoo.

The site shows galaxy images from the SDSS to the public and lets them classify them. Categories are very simple: spirals (subdivided into direction of rotation and edge-on), ellipticals, mergers and stars/unknown. The aim is, of course, to use the human brains’ excellent capability to recognise pattern, even if they are feeble. What a wonderful project! I am quite sure it will become popular and therefore successful.

As a “professional”, however, one gets into troubles when trying this myself. That’s because of a little too much background knowledge. Mainly, I find it hard to ignore the color of a galaxy or some other details that are visible. This probably biases my judgment more towards the “other” classification as compared to the more specific ones.

• Gibson & Schild
• http://arxiv.org/abs/0710.5449
• It’s about Stephans Quintet.
• This paper made it here simply because of the über-acronym CDMHCC in the abstract. It stands for cold dark matter hierarchical clustering cosmology.
• I have no clue about this “hydro-gravitational-dynamics” and “fluid-mechanical cosmology” though…

Everbody who reads the daily news on astrp-ph knows that there is a lot coming in and very little of it is really relevant for the own work.

I think I have found a decent solution to this. It uses Yahoo Pipes on the RSS feed from arxiv.org. Have a look at this screenshot from the interface:

It is as simple as telling Pipes to get the feed, filter it according to your needs and providing the output which you can in turn prenumerate with your favourite RSS or other news aggregator. I have created three such pipes for myself, one for a list of author names, one for keywords in the title or abstract and one for certain favourite astronomical objects that I work with.

This has reduced the number of papers that I have to check to around ten per day and the chances of them being relevant are usually quite good. Of course the results depend completely on your filter criteria and this whole thing might not be for you if you are afraid to miss something.

• Jesseit et al.
• http://arxiv.org/abs/astro-ph/0606144
• “real” simulations are the way to go for understanding the complex velocity fields of our BCGs.

• Belkus et al.
• http://arxiv.org/abs/astro-ph/0701334
• dense clusters
• supermassive stars