Notes on SEDs from BRC34

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  • 213309.7+580345 - ick! drop!
  • 213314.5+580351 - nice little one, check i2
  • 213327.2+580413 - nice little one
  • 213329.2+580250 - ogura 1 - nice one!
  • 213334.0+580418 - strange. check in images, track down why no 2mass, very likely garbage.
  • 213335.3+580647 - nice little one
  • 213336.2+580324 - also pretty nice, if real - check i3i4 phot, check location in m24. limits would be good to add to the SED here at m24.
  • 213337.3+580545 - icky, drop!
  • 213338.6+580627 - icky, drop!
  • 213340.8+580626 - pretty cute, check i2. check all irac bands?
  • 213340.8+580631 - nice little one
  • 213350.2+580326 - nice little one, though check i4.

NEW 9 NOV, LMR -- when going through this list, again and again, i noticed that the really big bright source in the heart of the BRC itself is not included on this list. Very peculiar. I got into the original source lists and discovered the following, not necessarily in this order, but close:

  • The source is very bright at IRAC bands, saturated in the long frames. Very bright sources are often YSOs, so let's chase this one down.
  • Source detection algorithms have a hard time with very bright sources, often finding false "clusters" of sources around a bright source, because of the complex shape of the PSF and/or saturation.
  • The individual source lists done per channel indeed have this problem, and because they are not real, not all of the sources were correctly matched to the 'real' source.
  • The 2mass frames are a good reference for the true position of the real source. The source does not appear in the J or H frames (more good evidence that it is a deeply embedded YSO!), but it does appear in K.
  • I went and extracted the photometry from the 2MASS catalog, being careful to keep track of coordinates and limits.
  • I went back to the IRAC source extractions. The source at this position in our catalogs has a successfully obtained i1i2i3 measurement, but no i4. The I4 measurement is somewhere else, too far away (more than 1 arcsec) for the computer to have matched it to this source.
  • The MIPS source extractions have a larger coordinate uncertainty, and as such the MIPS-24 source here got incorrectly matched to a false nearby source.
  • There is a MIPS-70 source here too! That also did not get matched properly.
  • I went and redid the i4 aperture photometry at the correct location.
  • I went and manually forced the M24 and M70 detections to match to the correct object.
  • The new source is very likely a new YSO, and should definitely be added to our 'keep' list. It has a gorgeous SED. Optical spectroscopic followup will be next to impossible, given how faint it is in the NIR. Even NIR spectroscopic followup will be quite challenging. It's like 5 Jy at 70 um. Perhaps we can beg SOFIA DDT time for him.
  • LESSON TO BE TAKEN FROM THIS -- this is, always will be, a recursive process. Keep going back through, again and again, applying your brain at all stages. Really look at all the images and the catalogs, and just because the computer says it does not mean it's right.

NOTES DEC 13 -- i finally got to going through your notes. only tagging ones needing additional notes.

  • 213332.2+580329 -- someone asked about saturation in this obj , which is the 5th one on the xls list. yes, it is probably saturated in the long integration. but remember that at each position, you have both a long and a short integration time. the short integration mosaic is called somehing like brc34_i3_shortmosaic.fits, as opposed to brc34_i3_mosaic.fits.
  • 213334.0+580418 -- wow, i would still tag this as very marginal. it's really not there in the POSS and 2MASS images, which is kind of unusual for a legitimate young star, but not unheard of. Looking at the IRAC images, i agree its placement in the nebulosity is suggestive, but damn; it falls off like a rock after i2. i am not at all sure what's going on with this source, and it's going to be darn hard to get follow-up data on him because he is quite faint in the optical and NIR, really at all bands here. If I had to bet money, i'd bet on contaminant.
  • 213335.3+580647 -- someone said 'no mips' but there is mips data here, just not a detection (that's an important distinction -- no data vs. no detection). dropped an aperture to get an upper limit here.
  • 213336.2+580324 -- same for this one. getting a MIPS limit. Also, he has a friend nearby of comparable brightness -- what does his SED look like? he is 213336.8+580329, it does look like a nice SED, and for some reason, the gutermuth yso calculation failed for him. i don't know why. ah, wait, yes I do. it failed the second equation group because i2 lt 11.5 (it is 12.4). However, the original guy is also this faint. hm. Ah, ok, he fails one of the Class 0/1/flat tests. He is faint, but comparable in brightness to the friend who did get tagged. I'm going to add him to our list of candidates just based on proximity and similarity to the other one.

Looking at location in the images:

  • 213350.2+580326 -- is really badly on the edge at i1, but the SED seems like it might be ok. keeping but i don't feel great about it! ;) it is a long way from the nebulosity, too. not impossible, but ...?
  • 213309.7+580345 -- i think we have tagged as drop. i'm ok with this based on where it is in the image - it's way on the edge, away from the others.
  • 213334.0+580418 -- in the middle of the neb, but damn faint. ok with me to drop.
  • 213338.6+580627 and 213337.3+580545 -- both on a ridge of nebulosity; suspicious. BUT I don't really see point sources here. I think these are indeed spurious, droppable sources.

Looking at location in the CMDs, CCDs: I'm happy with the locations of all our 'keeps' and 'drops'.