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Urgent! NSv 6690 imminent SMBHB merger confirmation needed

Posted: Tue Feb 08, 2022 2:01 pm
by Robin Leadbeater
A recently published paper suggests there may be a supermassive black hole merger in the Seyfert Galaxy SDSSJ1430+2303 (NSV 6690 in VSX) in the next three years or possibly even sooner- within 100-300 days.
https://arxiv.org/abs/2201.11633
A low resolution spectrum from last night (ALPY200) suggests a change in the H alpha line profile on the blue edge in the past few weeks but the SNR is poor.
The lead author of the paper, Ning Jiang has requested a confirming spectrum before arranging a high resolution follow up but my weather is not good. Would anyone else (Etienne :) ? like to try ?
The spectrum and finder image can be seen here on my BAA page and is available to download from the BAA database
https://britastro.org/observations/obse ... 59183a3d41
Note this is a faint extended object at integrated ~mag 16-17 so challenging my total exposure was 3 hours but conditions were not perfect

Cheers
Robin

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Tue Feb 08, 2022 5:57 pm
by etienne bertrand
Hello Robin !

Thanks for you words, i want try it !
I send to you the spectr when it take it ?

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Tue Feb 08, 2022 7:25 pm
by Robin Leadbeater
etienne bertrand wrote:
Thanks for you words, i want try it !
I send to you the spectr when it take it ?
I knew you would like the challenge :-)

Yes you can contact me on the email on my website

Cheers
Robin

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Wed Feb 09, 2022 4:14 am
by Rainer Ehlert
Robin Leadbeater wrote:A recently published paper suggests there may be a supermassive black hole merger in the Seyfert Galaxy SDSSJ1430+2303 (NSV 6690 in VSX) in the next three years or possibly even sooner- within 100-300 days.
https://arxiv.org/abs/2201.11633
A low resolution spectrum from last night (ALPY200) suggests a change in the H alpha line profile on the blue edge in the past few weeks but the SNR is poor.
The lead author of the paper, Ning Jiang has requested a confirming spectrum before arranging a high resolution follow up but my weather is not good. Would anyone else (Etienne :) ? like to try ?
The spectrum and finder image can be seen here on my BAA page and is available to download from the BAA database
https://britastro.org/observations/obse ... 59183a3d41
Note this is a faint extended object at integrated ~mag 16-17 so challenging my total exposure was 3 hours but conditions were not perfect

Cheers
Robin
Hi Robin,

Is that PGC 214276 ? Sorry for the dumb question. That is what I deducted from your finder image.

Mag 16.7 is quite dimm. I think I will not reach it. :cry:

Thanks

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Wed Feb 09, 2022 11:57 am
by Robin Leadbeater
Rainer Ehlert wrote:
Is that PGC 214276 ?
Yes that's the one PGC 214276 (2MASS J14301603+2303445)

Cheers
Robin

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Wed Feb 09, 2022 6:42 pm
by Robin Leadbeater
Note there are a strong telluric bands in the region where the red shifted H alpha line falls so either remove them by including them in the response correction or divide them out using a template prepared from the reference star.
Tellurics.png
Tellurics.png (6.28 KiB) Viewed 7129 times

Cheers
Robin

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Thu Feb 10, 2022 10:05 pm
by etienne bertrand
Yes thanks Robin !

I try when i have good sky. The emission is very intense on your aquisition on the image or very faint ?

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Fri Feb 11, 2022 12:13 am
by Robin Leadbeater
etienne bertrand wrote:Yes thanks Robin !

The emission is very intense on your aquisition on the image or very faint ?
The redshifted H alpha peaks about 50% above the continuum in my R~130 ALPY200 spectrum but it is not obvious in a single raw image. (the air glow and telluric bands make it difficult to spot, think.) Here is the finals spectrum and a single 1200s image (dark and cosmetic subtracted)
NSV6690_1200s_image_1080s_spectrum.png
NSV6690_1200s_image_1080s_spectrum.png (381.9 KiB) Viewed 7068 times

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Sat Feb 12, 2022 2:26 pm
by Robin Leadbeater
I managed to get another spectrum. The feature on the blue wing is not so obvious (The SNR in the mean spectrum is still only ~20 at that wavelength)
nsv6690_20220206-10_mean.png
nsv6690_20220206-10_mean.png (35.86 KiB) Viewed 6978 times
but there is still perhaps a difference compared to the the spectrum in the paper (in grey).
NSV6690_mean_20220206-10_dec_2021_overlay.png
NSV6690_mean_20220206-10_dec_2021_overlay.png (33.07 KiB) Viewed 6978 times

Re: Urgent! NSv 6690 imminent SMBHB merger confirmation nee

Posted: Sat Feb 12, 2022 7:38 pm
by Joan Guarro Flo
How always, a fine job, Robin !

That observation is very difficult. Congratulations !

Joan.