Author Topic: Hubble and Voorwerpjes!  (Read 25649 times)

paulrogers

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Re: Hubble and Voorwerpjes!
« Reply #30 on: June 11, 2011, 04:05:39 am »
That's odd - I see it with black font on a scrollable cream background, both using Mac/Safari and WinXP/Firefox. Anyone else having this issue?
I don't get the cream background.  It looks like part of an overblown, pixelated spiral galaxy.  Or perhaps one painted by Monet.

c_cld

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Re: Hubble and Voorwerpjes!
« Reply #31 on: June 12, 2011, 08:17:37 pm »
More information, including which galaxies we plan to observe, now on the blog. It runs to less than 900 words, rather than my frequent 2000+, so I must have been feeling a bit terse today.
Hi Bill,
Let me recall your March 23 msg:
That latest paper - on the QSO ionizing a tidal tail and gas in the companion, at z=0.37 - is a striking instance of something we see in the Voorwerpje sample (and in fact I just added that reference to the draft). The easiest way to put a lot of cold gas in a position to be ionized by an AGN that far out seems to be a galaxy encounter pulling out a gas-rich tidal stream. If we knew enough of these, they might give us a way to look at the angular pattern of emerging radiation, seeing which parts of the gas stream are and are not ionized.
the paper was arXiv:1103.4134v1: Shining Light on Merging Galaxies I: The Ongoing Merger of a Quasar with a `Green Valley' Galaxy and the QSO host galaxy 1237663543138320633 SDSS J204956.61-001201.7

Have you put aside this object already investigated or too far?

What about the same kind cited after your msg in the same OOTD thread:
Object in DR8 1237655369825780205 or DR7 588011123577586125 photoZ  0.25896
and ACS/WFC G800L GRISM 1D spectrum (fits file) HAG_J123616.05+621927.8_J8HQAAKAQ


Thanks and congratulations on your granted lot of HST orbits for shooting many objects with sufficient exposure time.
c_cld




« Last Edit: June 12, 2011, 08:29:39 pm by c_cld »

zutopian

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Re: Hubble and Voorwerpjes!
« Reply #32 on: June 13, 2011, 04:55:39 pm »
Hubble* versus SDSS image of a possible Voorwerpje: 
* "just" a Zoo image



587726033309073474 z=0.079

Here is the Hubble Zoo image:


http://www.galaxyzoo.org/examine/AHZ2001iu5

zutopian

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Re: Hubble and Voorwerpjes!
« Reply #33 on: June 14, 2011, 12:05:16 pm »
There is a very interesting news at "Universetoday": It is about the new discovery, that NGC 3758 aka Markarian 739 has binary AGN.
However, it isn't one of the discovered GZ Voorwerpjes, but I hope, that the HubbleST will look at it also soon.

Actually, Mkn 739 is one of the 19 confirmed GZ Voorwerpje systems, but its energy balance makes it pretty clear that the AGN we see is responsible for the ionized gas clouds on its rim, so there wasn't enough of a question of luminosity changes to include in the Hubble proposal. Unusually among the GZ Voorwepje nuclei, it has a type 1 Seyfert nucleus where we have a fairly direct view of the area around the central black hole, so we see the very broad emission lines from its inner regions.

The title of the paper is "Chandra Discovery of a Binary AGN in Mrk 739" and one of the authors is Kevin Schawinski.
http://arxiv.org/abs/1106.2163

zookeeperKevin

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Re: Hubble and Voorwerpjes!
« Reply #34 on: July 25, 2011, 09:19:24 am »
In the case of Mkn 739 it's likely that the unobscured AGN is doing the ionizing...

sdrew123

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Re: Hubble and Voorwerpjes!
« Reply #35 on: August 06, 2011, 07:29:23 pm »
Greetings Voorwerpje Hunters,

Whereas the voorwerpje journal paper will focus on the 19 confirmed voorwerpje hosts, I have created a webpage showing ALL of the results from last summer's voorwerpje survey. The page includes spectra from the ~30 or so galaxies targeted as potential voorwerpje hosts, spectra from targets suggested by GZ forum regulars while we were actually at the telescope, and finally, a handful of spectra from objects we looked at just for fun (like Neptune). If you're curious about how the confirmed voorwerpjes were actually confirmed, or if you just enjoy looking at AGN spectra, the page is here - http://wwwstu.tcu.edu/drewchojnowski/AGNspectra1.html.

- Drew

mitch

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Re: Hubble and Voorwerpjes!
« Reply #36 on: August 06, 2011, 08:44:33 pm »
Thanks a lot Drew - terrific work  8) 8) 8)

Alice

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Re: Hubble and Voorwerpjes!
« Reply #37 on: August 06, 2011, 10:24:37 pm »
This is just wonderful! I've done a quick Object of the Day about it. Thank you so much Drew. 8) ;D

I'm probably just being daft but I couldn't find Neptune anywhere :-\ Update: doh! Here it is! :D
« Last Edit: August 07, 2011, 12:53:02 am by Alice »

NGC3314

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Re: Hubble and Voorwerpjes!
« Reply #38 on: October 31, 2011, 08:21:28 pm »
Counting down - the first Hubble observations of a Voorwerpje are coming up, namely images of SDSS J220141.64+115124.3 (ObjID 587727221400862869) scheduled for November 8. Then we get a long time to contemplate those - the other 6 will trickle in from about April to December of 2012.

JeanTate

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The Galaxy Zoo survey for giant AGN-ionized clouds
« Reply #39 on: November 01, 2011, 01:25:41 am »
Full title: The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black-hole accretion events

Authors: William C. Keel, S. Drew Chojnowski, Vardha N. Bennert, Kevin Schawinski, Chris J. Lintott, Stuart Lynn, Anna Pancoast, Chelsea Harris, A.M. Nierenberg, Alessandro Sonnenfeld, Richard Proctor

Comments:    Accepted by MNRAS. Reduced-resolution figures; full-resolution PDF file available until publication at this http URL
Cite as:    arXiv:1110.6921v1 [astro-ph.CO]

Submission history
From: William C. Keel
[v1] Mon, 31 Oct 2011 19:53:47 GMT

And the abstract:
Quote
Some active galactic nuclei (AGN) are surrounded by extended emission-line regions (EELRs), which trace both the illumination pattern of escaping radiation and its history over the light-travel time from the AGN to the gas. From a new set of such EELRs, we present evidence that the AGN in many Seyfert galaxies undergo luminous episodes 20,000-200,000 years in duration. Motivated by the discovery of the spectacular nebula known as Hanny's Voorwerp, ionized by a powerful AGN which has apparently faded dramatically within ~ 100,000 years, Galaxy Zoo volunteers have carried out both targeted and serendipitous searches for similar emission-line clouds around low-redshift galaxies.We present the resulting list of candidates and describe spectroscopy identifying 19 galaxies with AGN-ionized regions at projected radii > 10 kpc. This search recovered known EELRs and identified additional previously unknown cases, one with detected emission to r = 37 kpc. At least 14/19 are in interacting or merging systems; tidal tails are a prime source of extraplanar ionized gas. We see a mix of one- and two-sided structures, with observed cone angles from 23-112 degrees. We consider the energy balance in the ionized clouds, with lower and upper bounds on ionizing luminosity from recombination and ionization-parameter arguments, and estimate the luminosity of the core from the far-infrared data. The implied ratio of ionizing radiation seen by the clouds to that emitted by the nucleus, for a constant nuclear source, ranges from 0.02 to > 12; 7/19 exceed unity. Small values imply heavily obscured AGN. However, large values may require that the AGN has faded over tens of thousands of years, giving us several examples of systems in which such dramatic long-period variation has occurred; this is the only current technique for addressing these timescales in AGN history. (Abridged)

zutopian

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Re: Hubble and Voorwerpjes!
« Reply #40 on: November 01, 2011, 06:28:33 am »
Voorwerpje paper:
Quote
In both Mkn 463 and Mkn 739, Chandra imaging has furnished evidence for double AGN (Koss et al. 2011, Bianchi et al. 2008).

According to below quote NGC 5256 aka Mkn 266 has also a double AGN, hasn't it?

HubbleSite NewsCenter: Release Date: April 24, 2008:
Quote
NGC 5256 is located in the constellation of Ursa Major, the Great Bear, some 350 million light-years from Earth. Each galaxy also contains an active galactic nucleus, evidence that the chaos is allowing gas to fall into the regions around central black holes as well as feeding starbursts. Recent observations from the Chandra X-ray Observatory show that both nuclei, as well as a region of hot gas in between them, have been heated by the shock waves driven as gas clouds at high velocities collide.
http://hubblesite.org/newscenter/archive/releases/2008/16/image/bt/
« Last Edit: November 01, 2011, 09:09:29 am by zutopian »

NGC3314

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Re: Hubble and Voorwerpjes!
« Reply #41 on: November 01, 2011, 02:17:11 pm »
What's the emoticon for "hitting self over head with a plank"? If we have scope to actually add things in proofs , I might have to fix that. At least it was only an aside rather than a major point...

By the way, there is more discussion on the blog.

zutopian

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Re: Hubble and Voorwerpjes!
« Reply #42 on: November 01, 2011, 05:02:20 pm »
Referring to my previous post concerning NGC 5256 aka Mkn 266:

In DR7 there is given spectra for each nucleus.
This galaxy is presented in a new paper (one of the galaxies in figure 6). I recently discussed with sdrew on the forum about another (controversial) galaxy from that paper:
http://www.galaxyzooforum.org/index.php?topic=10662.1470
"Active Galactic Nucleus Pairs from the Sloan Digital Sky Survey. I. The Frequency on ~ 5-100 kpc Scales"
Authors: Xin Liu, Yue Shen, Michael A. Strauss, Lei Hao
(Submitted on 5 Apr 2011 (v1), last revised 14 Jul 2011 (this version, v2))
http://arxiv.org/abs/1104.0950

Besides I found another paper in ADS:
Quote
Our studies suggest that Mrk 266 might be a new candidate in hosting binary AGNs supported by X-ray observations.
"Chandra archival study of (U)LIRGs with a double nucleus: binary AGNs?"
Authors: Wang, Jing-Bo; Gao, Yu
Publication: Research in Astronomy and Astrophysics, Volume 10, Issue 4, pp. 309-328 (2010).
Publication Date: 04/2010
http://adsabs.harvard.edu/abs/2010RAA....10..309W



NGC3314

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Re: Hubble and Voorwerpjes!
« Reply #43 on: November 01, 2011, 06:20:42 pm »
Forgot to add - at the risk of being coy, there is another Zoo paper about to be submitted that bears on this issue of how often we see binary AGN.

zookeeperKevin

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Re: Hubble and Voorwerpjes!
« Reply #44 on: November 01, 2011, 06:23:22 pm »
Forgot to add - at the risk of being coy, there is another Zoo paper about to be submitted that bears on this issue of how often we see binary AGN.

Yup.

Though apparently the first author needs to do some paperwork first...