Author Topic: Wednesday, 2 July, 2014: Depth  (Read 1881 times)

JeanTate

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Wednesday, 2 July, 2014: Depth
« on: July 02, 2014, 12:18:59 am »
Back in the good ol' days, Object of the Day featured a single image, often with a single object of note. Today's OotD is a return to that style.



In this one image, we go from an asteroid in our own solar system, to a star in our own galaxy (complete with diffspikes)



To a nearby galaxy (redshift 0.019), and one not so nearby (z=0.084) with an active nucleus (probably a starburst, rather than an AGN)




To a rich cluster far in the background (z=0.371):



To a mystery:



Thanks to zooite 1001G for posting this in Radio Galaxy Zoo Talk, 1 RADIO SOURCE GALAXY & SPIRAL GALAXIES.

The red contour lines are from a FITS I downloaded from SkyView, using the VLA FIRST (1.4 GHz) survey, and which I processed using Python (some details in the RGZ Talk thread How to decide the 'zero point' for radio contours?).

The mystery? The apparent source of the strong radio emission seen by FIRST is SDSS J103250.26+155116.8, which SDSS thinks is a STAR. As we have learned, over in Radio Galaxy Zoo, these often turn out to be quasars, far in the background (z>~1.5). In this case, the mystery isn't just whether that 'star' is, in fact, the source of the radio emission; it's also what sort of emission it is! Is it #corejet? Or a #wat? Or something else?

What mysterious objects can you find, among the Radio Galaxy Zoo images?

minor note: the scale bar is ~1.5% too small (not that you could tell)

planetaryscience

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Re: Wednesday, 2 July, 2014: Depth
« Reply #1 on: July 02, 2014, 12:20:21 am »
I've noticed that a large portion of the sources for radio emission in RGZ are from distant quasars rather than nearby ellipticals or spirals as we would expect. Sine so many of these distant objects seem to increase in average radio emission the further out they are, I think it might be safe to assume that, bringing together rick's topic of whether QSOs are first generation events, and I would say for a small degree of certainty, yes. You find many quasars around Z=1+, several billion light-years away, yet in your picture of a nearby spiral and another spiral ~7x further out, you find that the spiral has much less emission than the other, more distant, galaxy, which in turn has much, much less emission than the nearly-invisible distant quasar. Frankly, I think that galaxies have some sort of material that early-stage black holes feed off of, possibly hydrogen, that early galaxies will shoot of extreme amounts of early in their life, sort of as a christening of a new galaxy if you will. Images of ours and other galaxies show there to be a cavity of gas and absence of stars in close vicinity to a supermassive black hole, and it's typically thought to be caused by the 'wind' emitted from it, but could it simply be the absence of gas that was pulled into the black hole early in its life, and later pushed out? These are all just speculation based on a small amount of observation, but it's possible some of this could have some real scientific grounding, and is something to be considered.
I like to find asteroids and galaxy mergers- but all galaxies are still fine to me.

elizabeth

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Re: Wednesday, 2 July, 2014: Depth
« Reply #2 on: July 03, 2014, 02:49:06 am »
 :) Just wondering has that asteroid been posted?

JeanTate

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Re: Wednesday, 2 July, 2014: Depth
« Reply #3 on: July 03, 2014, 12:48:46 pm »
Thanks!

@elizabeth: I have no idea.  :(

@planetaryscience: as far as I know, there are a great many papers on such questions. Once the RGZ classifications are done, I expect our clicks - as data - may be used as the basis for yet more papers. However, I suspect the click data would need to be analyzed together with data from other sources, to move this forward.

In RGZ Talk, there's a section called Journal Club, and recently 42jkb posted Suppression of star formation in early-type galaxies by feedback from supermassive black holes, by zkKevin+ 2006, as a paper for the club to discuss. Why not come on over and join in?  :)