Starburst "nucleus"

by Budgieye moderator

See how different it looks in different surveys. It is a "close" galaxy z=0.003

enter image description here AGZ

http://zooniverse-static.s3.amazonaws.com/www.galaxyzoo.org/subjects/standard/56f3db205925d9004201a233.jpeg

enter image description here DECaLS dr2

http://legacysurvey.org/viewer/jpeg-cutout/?ra=178.5509&dec=0.1356&zoom=14&layer=decals-dr2

enter image description here SDSS dr9

http://skyservice.pha.jhu.edu/DR9/ImgCutout/getjpeg.aspx?ra=178.55113836&dec=0.13662968&scale=0.2&width=200&height=200&opt=G

http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?ra=178.55114444142401&dec=0.1366390399628611

enter image description here

http://skyserver.sdss.org/dr9/en/get/specById.asp?id=320977163341817856

It has a lot of starburst, which seems to be close to the center of the galaxy.And lots of hot hydrogen, almost quasar - like.

useful info.

Astrophysics for Galaxy Zoo Talk Galaxy Redshift Chart for SDSS http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=2

Posted June 19, 2016 7:20 PM

by ElisabethB moderator

So, we have a very bright nucleus ! 😄

Posted June 19, 2016 7:27 PM

by elsie22

wow that's awesome. I really thought you were going to say it was a star in the way. so how do you know it has a lot of Starburst? and when it says 'warning many outliers' are they the chemicals on the graph with red lines pointing at them?

Posted June 19, 2016 9:14 PM

by Budgieye moderator

You may still be correct. The analysis on these spectral charts can be wrong. The software can be fooled by something unexpected, like a blue star in front of a galaxy . We may need to call in a scientist, but let's try on our own.

Page 3 Spectra Guide for Galaxy Zoo Talk http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3

Starburst is measured by the amount of blue around 4000 and 5000 Å, The blue in our chart can be from starburst, or from a foreground blue star. eg http://skyserver.sdss.org/dr10/en/tools/explore/summary.aspx?id=0x112d13df8081004b&spec=0x22a0310ed3006800&apid=

If there are emission lines, the redshift can be calculated from that, since it gives more accurate results. Since the emission lines of hydrogen are labelled in blue, and the absorption lines are outlined in red seems to be in general agreement, except for some unexplained outliers. I think the emission lines are at 0.003, and therefore from the galaxy, although I haven't checked up on the data.

Starburst is explained by the OIII peak. Lots of stars made = lots of stars exploding = lots of hot nebulae with hot oxygen

There is a lot of very hot hydrogen producing emission lines. I would suspect that the nucleus is very active, and spraying the local hydrogen with UV, which makes it emit light in characteristic peaks

Hα

Hβ

H γ

H δ

Hε

So I would think that it is a starburst galaxy near an active nucleus, but I haven't explained the outliers.

Here is a similar galaxy

enter image description here