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Date and Time of the Query: 2019-08-22 T18:25:50 PDT
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Notes for object HUDF-JD2

1 note(s) found in NED.


1. 2008ApJ...676..781W
Re:[WDF2008]:BBG 3179
[WDF2008]:BBG 3179.-This object is detected by MIPS at 24 microns. This object
is also known as HUDF-JD2 and discussed in Mobasher et al. (2005). It is
situated ~7" from a foreground galaxy. In the HUDF, JD2 is undetected in all
four ACS bands at AB magnitudes >~30 (see Table 2). However, in our K-selected
catalog, based on the shallower GOODS data, it is flagged as a tentative
detection in the Viz bands. Using the latter photometry results in a photometric
redshift z = 5.1, a stellar mass of 5 x 10^11^M_sun_, and an age for the stellar
population of 2 Gyr. This age is well in excess of the age of the universe, and
BBG 3179 is the only candidate in our sample that violates the cosmological age
restriction. The SED fit has a {chi}^2^ ~ 5, and the Monte Carlo simulations
give a wide redshift distribution. Inspection of the UDF ACS/NICMOS images
reveals that BBG 3179 is surrounded by several faint neighboring galaxies,
affecting the aperture-based flux estimates. Careful subtraction of the
neighbors was done on the UDF data (Mobasher et al. 2005), leading to upper
limits to all four ACS bands and a photometric redshift z = 6.5. While the
stellar mass in this case is comparable to what we find using the GOODS data,
the age is found to be 0.6-1.0 Gyr. In the remainder of this work we base the
JD2 results on the UDF data. A recent analysis of this galaxy by Dunlop et al.
(2007) gives the same results as found in Mobasher et al. (2005) when using the
same photometric data. In addition, Dunlop et al. (2007) make an independent
assessment of the ACS data where JD2 is assumed detected in the Viz bands
(albeit well below 3 {sigma}), at levels ~0.8 mag brighter than in the Mobasher
et al. (2005) analysis of the HUDF data. With this set of ACS photometric data,
Dunlop et al. (2007) find a best-fit photometric redshift z_phot_ ~ 2.2.


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