Very red starburst galaxy

by CeciliaB

I am wondering what makes the small starburst galaxy in between the two big galaxies glow in such a very bright red colour in SDSS.

The spectrum shows a high hydrogen emission line which is slightly broadened at the base, so perhaps it's an AGN we are looking at.

The redshift is 0.07, but all AGN's are not as red as this one at that distance. I'm not sure if there is an influence from the other emission lines in the spectrum (OII and OIII) in this case.

Posted August 1, 2017 6:00 PM

by Budgieye moderator

I couldn't get far with this. Any other opinions

The red colour comes from hot hydrogen,

Is the AGN. around the black hole of the nucleus. But why is the entire little galaxy the same colour?

Is it a voorwerp being created? One could always hope. The GAMA images seems to show a succession of similar structures.

purple pea see similar object but with more hydrogen http://skyserver.sdss.org/dr10/en/tools/explore/summary.aspx?id=0x112d06c1615c0070&spec=0x071c124775006800&apid=

NED reference has 4000 objects

enter image description here

There seems to be some interfering black in the way in both GAMA and SDSS images

http://skyservice.pha.jhu.edu/DR9/ImgCutout/getjpeg.aspx?ra=178.44414696&dec=1.19085082&scale=0.2&width=200&height=200&opt=G

enter image description here

Nothing much nearby

enter image description here

The hydrogen and oxygen peaks are very high and narrow.

in SDSS DR7

enter image description here

http://cas.sdss.org/dr7/en/tools/explore/obj.asp?id=588848901522587714

Posted August 1, 2017 6:26 PM

by Ghost_Sheep_SWR in response to Budgieye's comment.

The GAMA images seems to show a succession of similar structures.

Ah yes I see what you mean now , roughly 3 clumps in a vertical row with the central biggest one on the bottom.

I think that could also make it interesting for the cross-ionization search because of the same-coloured upper side / spiral arm of the smaller companion at 4:00.

Posted August 1, 2017 7:29 PM

by Budgieye moderator

Spectra of Hanny's Voorwerp for comparison. The hydrogen peak is lower

enter image description here

Posted August 1, 2017 8:00 PM

by Ghost_Sheep_SWR

Strange...

enter image description here

enter image description here http://skyserver.sdss.org/dr14/en/tools/explore/Summary.aspx?sid=4327005778995027968

enter image description here http://skyserver.sdss.org/dr14/en/tools/explore/Summary.aspx?id=1237671126979117210

Posted August 1, 2017 8:38 PM

by Budgieye moderator

Thank you for finding the dr14 spectrum. It is easier to look at.

Posted August 1, 2017 9:02 PM

by Ghost_Sheep_SWR

Well two actually, which one is 'true' (better)?

Posted August 1, 2017 9:17 PM

by Budgieye moderator

We will ask a scientist.

Posted August 2, 2017 10:52 AM

by bluemagi

I thought I'd have a go at this or to say, I'll stick my neck out. Why is the galaxy so bright? Emission of light is caused by high temperature which comes from the supernova explosions within the Purple Pea. Outflows from the Pea are being captured by both galaxies. Thats it. Magi

Posted August 4, 2017 11:02 AM