From: Rachel G. (gibbo@panisse.lbl.gov)
Date: Wed Apr 14 2004 - 20:14:15 PDT
Lou,
Thanks for your prompt (and thorough) reply. I suppose
you can tell I haven't dealt with an IAUC before. Just a
quick response to something I can answer immediately about
candidates we left out. "Pine" and "Mahogony" both are
on-core (whatever that means for these galaxies) events and
might, therefore, make it difficult to convince people
they're not AGN activity, but I don't actually have any
other good reason to not include them. I remember now we
weren't sure what to make of "Cobi" because there was
nothing in our subtractions at the position you gave us.
Tomorrow morning I can make a postage stamp for you of what
we looked at. The coordinates we had for that one were:
(RA, Dec) = (12:36:06.5, +62:12:53.2).
Rachel
On Wed, 14 Apr 2004, Louis Strolger wrote:
> Hi Rachel,
>
> I think there are a few things that should be changed before it is
> submitted.
>
> You should probably remove the Host types, photo-z's, and possibly i'
> magnitudes. The galaxy type is very complicated, e. g. how do you apply
> Hubble type to galaxies at these redshifts? There are a few other, more
> indicative ways to classify galaxies at these redshifts and to compare
> them to samples at low redshift, e. g. Concentration- asymmetry and
> GALFIT parameters. This information should go into a paper when it is
> throughly done. The phot-z's are often accurate, but generally
> imprecise. We'll (you'll) get better redshift information in the
> future, and that too should go in a paper. You probably don't want
> imprecise info to appear in print, and then have some referee call you
> on inconsistencies in the future. Also, people can (and probably will)
> guess at the SN type from the info you've given, and more dangerously,
> try and determine cosmological parameters before you've had a chance
> to. For example, acs04-181 with a phot-z of 1.52, z ~ 25.7, and i-z~1
> sounds like a SN Ia at max! You've given a redshift and a measured
> magnitude, which I can turn into a distance and calculate a cosmology.
> i' magnitudes are not necessary.
>
> You probably want to add N-E offsets (from the hosts in individual
> columns), UT Date/time of discovery, magnitude limits (and mean UT) in
> the template image. Also, an additional decimal place in coordinate
> precision (the offsets are 1/100th of 1 arcsec, perhaps the coordinates
> should be 1/10 of 1 arcsec?). These things are in every IAU and Dan
> Green will demand that they are present. Also, I think there should be
> some statements on how these SNe were discovered. It should be
> mentioned that the SNe were found through difference imaging, and that
> the SNe were detected (to > 5 sigma ?) in each of the independent
> dithered exposures (total exposure time of ~3200 sec spanning ~1 hour
> of acquisition). It would also be a good idea to say something about
> why we believe these are SNe and not solar system objects or AGN, as we
> do not have spectroscopic confirmation for any of these (this was an
> early stumbling block with Dan, and could alleviate a similar problem
> for this new announcement).
> A good example of an IAUC announcement can be found on
> http://cfa-www.harvard.edu/iauc/07900/07981.html
>
> There are also other SNe that didn't make your announcement. We have,
> in addition to these 10, three others:
>
> Cobi 12:38:06.3 +62:12:53.38
> Pine 12:37:06.7 +62:21:17.82
> Mahogany 12:37:22.7 +62:09:35.75
>
> Can these be included? Please also check your coordinates. At least Adu
> and Beckenbaurer were inconsistent with what I have.
>
>
> Lastly, is it possible to reduce the number of names associated with
> this announcement? Clearly there are individuals who should be credited
> for these discoveries, the P.I. (Saul), and anyone who directly
> participated in either reducing the data or combing thought it for SNe
> (e. g. yourself, Rob, Tony, etc.). But adding too many credits will
> just force Dan to edit this list himself, and I don't think you want
> that.
>
> On our end, the credit should be as follows: A. Riess, L. Strolger, H.
> Ferguson, T. Dahlen (STScI), and P. Challis (CfA). There are others,
> but for the sake of brevity, this should probably be enough.
>
> --------------
>
> > Supernovae Discovered with ACS on 2-4 April 2004
> >
> > R. Gibbons (LBL) and A. Riess (STScI), on behalf of
> > [ADD NAMES ADAM GIVES ME]
> > G. Aldering, A. Conley, M. Doi, V. Fadeyev, A. Fruchter, G. Goldhaber,
> > A. Goobar, N. Kashikawa, R. Knop, M. Kowalski, N. Kuznetsova, T.
> > Morokuma,
> > S. Perlmutter, A. Spadafora, V. Stanishev, L. Wang, and N. Yasuda,
> > report
> > the discovery of 10 supernovae found with the Advanced Camera for
> > Surveys
> > (ACS) on the Hubble Space Telescope during the period 02-04 April 2004.
> > Deep F850LP (z'-band) and F775W (i'-band) imaging taken of the GOODS
> > HDF-N
> > field were compared with the one year old GOODS survey data. The
> > search
> > limiting Vega magnitudes were z'=26.2 and i'=26.5. B. Mobasher
> > provided
> > host galaxy photometric redshifts and host galaxy types based on
> > results
> > from the GOODS survey. We report only those events with magnitudes and
> > colors which are consistent with the photometric redshifts. Supernova
> > are
> > sorted by right ascension.
> >
> > R.A. Decl. z' i' host host
> > for easy IDing
> > (J2000) (J2000) (Vega) (Vega) offset photo-z host type
> > by Lou and Adam
> > ---------- --------- ------ ------ ------ -------
> > ---------------- ---------------
> > acs04-193 12:36:20.0 +62:13:48 25.1 25.5 0.13'' 0.54 late-type
> > spiral "Maradona"
> > acs04-177 12:36:20.9 +62:10:20 25.4 26.3 0.67'' 1.10 irregular
> > "Adu"
> > acs04-176 12:36:25.9 +62:09:38 23.7 ** 0.64'' 0.74? irregular
> > "Pele"
> > acs04-194 12:36:27.2 +62:15:10 24.4 25.1 0.24'' 0.74 elliptical
> > "Chinalia"
> > acs04-185 12:36:29.3 +62:11:42 24.4 24.3 0.07'' ?? irregular
> > "Beckenbauer"
> > acs04-186 12:36:46.1 +62:16:26 25.8 ** 0.16'' 0.61 ?
> > acs04-181 12:36:49.4 +62:16:05 24.9 25.7 0.03'' 1.52 Sa/Sb
> > acs04-076 12:37:09.4 +62:22:16 25.1 26.5 0.82'' 1.61 elliptical
> > "Zamorano"
> > acs04-197 12:37:21.2 +62:09:36 25.7 >26.5 0.13'' 0.72 starburst
> > "Teak"
> > acs04-195 12:38:03.5 +62:17:13 24.7 25.2 1.02'' 0.53 Sa/Sb
> > "Salas"
> >
> > ** i' band data not available
> >
> > Photometric redshifts are generally known to better than +/-0.3 (95%
> > confidence). "?" or "??" denote redshifts or host types which are less
> > well constrained.
> >
> >
>
>
>
> -----
> Louis-Gregory Strolger
> STScI
>
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