Urgent! NSv 6690 imminent SMBHB merger confirmation needed

[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

[etienne bertrand]

Hello Robin !

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

[Robin Leadbeater]

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

[Rainer Ehlert]

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.

Thanks

[Robin Leadbeater]

Is that PGC 214276 ?

Yes that's the one PGC 214276 (2MASS J14301603+2303445)

Cheers
Robin

[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 (6.28 KiB) Viewed 13146 times

Cheers
Robin

[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 ?

[Robin Leadbeater]

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 (381.9 KiB) Viewed 13085 times

[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 (35.86 KiB) Viewed 12995 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 (33.07 KiB) Viewed 12995 times

[Joan Guarro Flo]

How always, a fine job, Robin !

That observation is very difficult. Congratulations !

Joan.