Block

Enclosed is the annual progress report for the subject I$O block entitled, 'Two Extremely Red Galaxies," (Principal Dr. Hora, Dr. and Dr. This report covers the attached :s the second year budget.

survey, xs.o .ofth. . umpean uuaranteed Time smce ur. Joseph is a c;o-mvcsugator on me _u rmmon.) trim _s a survey of an unbiased sample of spiral and lenlicular ge/axles selected from the Revised Shaptey-Ames Catalog. It is therefore optically-selected, with a bdghmess limit of blue magnitude = 12, and otherwise randomly chosen. The original sample included 150 galaxies, but this was reduced to 74 when the allocated observing time was expended because the ISO overheads encountered in flight were much larger than predicted.
During the period since the ISO grant has been in fore Dr. leseph has spent time on this project in the following ways. c) A dedicated ISOPHOT data reduction software package, the "PHOT In.te_ve Analysis" software (PIA) has been developed at the Max-Planck-In_mt fUr Amronorme (MPIA) at Heidelberg, Germany. Dr. Joseph has spent considerable time learning to use this package, which is essential for data reduction and calibration. However major problems with the cah'bration d_a in PIA were not undemtood and corrected unul Vemloa 6 was announced in PebmarY '97. Because there has been so much difficulty in getting believable results from the ISOPHOT data, Dr. Joseph spent overa week.at the ISOPltOT Dam Centle at MPIA_ to get the help and advice ofthepeoplemost expert m ISOPHOT d_ta reduction and calibration, as well as the very latest undemtmding of t_ ISOPHOT calibration issues. Thie was immensely helpful. Although there remain significa : e,dibration issues with ISOPHOT, the situation is now vastly improved. Dr. Joseph has now • mpletely reduced the _otometric data at 60 pro, 100 tun, and 185 pan for all 74 I_alaxies so far observed using the latest version of the PIA software, Version 6.3. Comparison with IRAS photometry at 60turn and 100 tun gives excellent agreement for galaxies which are unresolved by the ISOPHOT C,100 detector array. He will begin work on reducing and calibrating the I0 pm images talccn wxth ISOCAM for these 74 galaxies in tho coming year. We have not _ct begun reductions of our dam, since all of our ISOPHO_I/o_adons have been taken with the chopper medc (before optimized _ for talcing ooservadons o._ faint sources had bccn developed), and we wish to wait until the oest approaches to reaucmg such data are known. The PI plans m visit IPAC this Pall to do the _on.
In the meantime, we are trying to ensure that our remaining obP.m'vadons me carried out in a way that will optimize ourdetections.

4) T_e Spatial Distribution
of Cool Dust in Planetary Nebulae P.I.: .I,. Hera The computer hardware and software upgrades necessary for processing the ISO dam have been purch_._ed and installed. Some of the data in our proli_mn has been obtsincd by ISO, and recently it has been delivered to us in a use_le format, although the calibration is not yet certified as correct. We are beginning toanalyze theds_ and await the delive_of the remainder of our data set.

S) Search for Primeval
Galaxies and Studies of Extremely Red Galaxies in z _ 4 Quasar Fields P.I.: Esther I-In This task supports a .deep imaging search for high redshl/_ gala_.'es a_.+.unda z=4.7 quasar. usingISOCAM and investigation of thefar-IR s.pcctral energy _s_/..t_Uon.+ _. OC..Abl .ann. ISOPHOT) of extremely red galaxies in a second _.e quasar nel¢l, t,rettn_nary anaty.sn ISO data on the red galaxy field puts limits on the far IR.flu:x, all.d indi.cat_. tls.attll e_u galaxses are likely to represent a population of high.redshift eili_.,cals mm.er man Imp.' o_s. _t-. redde..ned objects. This interpretation is SUlrported by fol!,ow-up aeep.grouna-.o_, a &ecg imaging op this field, which has identified a numoer olomer extreme|y rm galaxses. surrounding the ISO field, suggesting a clustered, high-redshift red pop. utauon, m me ,... upcoming year we will concentrate on the analysis of the faint populadov3 in mese two tselOS as well as the detailed study of the red galaxies.