Next GZ Hangout: Friday, 8th March, 15:30 GMT
Next Galaxy Zoo Hangout: Friday, the 8th of March, 2013, 3:30 p.m. GMT
Want to contribute for our next hangout? Post your questions & comments below and/or feel free to tweet them @galaxyzoo or post them on Facebook.
Shortly before the hangout starts, we’ll embed the video in this post so you can watch from here. And during the chat, if we use a science term you aren’t familiar with, please use the Jargon Gong by tweeting us with a GONG (example: “@galaxyzoo GONG forbidden [OIII] atomic transition” — not that I’m quoting the last hangout or anything); we’ll be happy to explain!
Update: video now available at the hangout summary post!
Galaxy Zoo 
Hi
I have classified over 60,000 galaxies and only found 1200 merger’s wich i have collected over the years, and i have noticed about 90% are Barred Spiral Galaxies. Why is that.
Regards
Steve T
Since the chat will be on 8th March, the “International Women’s Day”, I would like to ask for statements about the situation of women in astronomy.
Can you please give a high-level explanation of how estimates of galaxies’ stellar masses are derived from SDSS photometry?
I have recently learned that, currently, in the MPA-JHU DR7 the stellar mass estimates are derived “using fits to the photometry” (source), but I do not understand – even at a high level – how this has been done.
I have come across the terms “specific star formation rate” (sSRF) and “star formation rate” (SFR), and understand the former is the latter divided by the stellar mass. While “specific” here has a meaning similar to that in, say, specific latent heat, it’s not really the same.
Why is stellar mass used, rather than total mass, or stellar+gas+dust (i.e. baryonic) mass? Is it because stellar mass is easier to estimate?
Will future telescopes be able to get a better view and images of FHB galaxies?
Thank you Bill, Brooke, Karen, Kevin, and Kyle. For (yet another) great Live Chat, and for having a go at answering my question.
I will have to play that part again, but from what I heard (and understood), estimating galaxies’ stellar masses from photometry is (or can be) a very convoluted process, involving a great many steps and assumptions (well, the full chain – from reduced photometry to estimates – is; in practice, I expect one can simple download a package, plug in the data, turn the handle, and out pops a result, nicely tied up with comforting sigma bows). And that one of the key assumptions concerns the IMF, a nice functional form that is, in fact, very poorly grounded in direct observational data.
Food for much thought.
In a future Live Chat, I do hope you can address Tom Freethesouls Zolotor’s question. If I may, I’ll add to it this: what have x-ray observatories such as XMM-Newton and Chandra, and IR ones such as WISE, Spitzer, Herschel and ALMA (both also a sub-mm/mm observatories) so far revealed about FHBs?