A Cm-Wavelength Search for Pre-Biotic Molecules in Starburst Galaxies: A Case Study for Zw in Starburst Galaxies: A Case Study for Zw Minchin R., Catinella B., Ghosh, T., Lebron M., Lerner M.S., Momjian E. O’Neil, K., Salter, C.J. (NAIC, NRAO, UPR and MPIfA) ‏ Interstellar organic species mostly form on the surface of dust grains and are then released into the gas phase by heating events. Organic species known as pre-biotic molecules may combine to form amino acids; one example is the combination of methanimine (CH 2 NH) and HCN on the path to glycine. Both CH 2 NHand HCN can be detected at cm-wavelengths, as we have demonstrated in Arp 220 (Salter et al 2008, AJ, 136, 389). Following this discovery, we have initiated observations of 40 Arp 220-like galaxies with Arecibo and the GBT. C-band observations with a frequency range of GHz cover both the CH 2 NH line and the HCN v2=1, J=4 transition. Observations and analysis are ongoing for both telescopes. In the data reduced so far, both CH 2 NH and HCN have been found in a number of sources, as have other molecules such as H 2 CO and excited OH, and hydrogen recombination lines. In this poster we present a case study for Zw Interstellar organic species mostly form on the surface of dust grains and are then released into the gas phase by heating events. Organic species known as pre-biotic molecules may combine to form amino acids; one example is the combination of methanimine (CH 2 NH) and HCN on the path to glycine. Both CH 2 NH and HCN can be detected at cm-wavelengths, as we have demonstrated in Arp 220 (Salter et al 2008, AJ, 136, 389). Following this discovery, we have initiated observations of 40 Arp 220-like galaxies with Arecibo and the GBT. C-band observations with a frequency range of GHz cover both the CH 2 NH line and the HCN v2=1, J=4 transition. Observations and analysis are ongoing for both telescopes. In the data reduced so far, both CH 2 NH and HCN have been found in a number of sources, as have other molecules such as H 2 CO and excited OH, and hydrogen recombination lines. In this poster we present a case study for Zw  -cm Excited OH Absorption Lines The λ6-cm lines of the excited-OH Transitions 2 П ½,,J=1/2,F=0-1,1-1 and 1-0 have intensity ratios close to 1:2:1, the LTE values. The OH lines at 4750 & 4765 MHz were heavily affected by RFI, and only 20 min of good ON-source data was usable. a Zw Zw (IRAS ; z = ) appears as a highly inclined disk with a smooth light distribution at large radii, but a bright arm of star formation ~1“ south of the 2.2-μm peak. ZW is classified as both an HII and a Luminous IR Galaxy (LIRG), and is also a strong OH Megamaser emitter. The galaxy was one of the sources included in the Arecibo part of the sample, and 1.25 hr of ON-source data were acquired for the object. The Sample Our sample of 40 Arp-220-like galaxies were selected from the lists of; OH Megamaser galaxies as compiled by Chen et al. (2007) Starbursts with detected H 2 CO masers or absorption (Araya et al. 2004) ULIRGS with direct evidence of nuclear starbursts (Armus et al.1990) FIR-luminous merging galaxies (Condon et al. 1991) Spectra were recorded from 8 × 100- MHz C-band band-passes that included lines either seen in Arp 220, or felt to be good candidates for detection. The objective was to obtain ~1 hr of ON- source integration on each target. The spectra here have ~30 km/s resolution MHz satellite line 4750-MHz main line 4765-MHz satellite line Formaldehyde (H2CO) The H 2 CO line in Zw was previously detected by Araya et al. (2004) and Baan et al. (1993). However, our line shape appears somewhat different to that of Araya et al. The possibility of variability needs investigation. Methanimine (CH 2 NH) Hydrogen Cyanide (HCN; v 2 =1) A Molecular Comparison with Arp 220 All molecular lines seen in our bands in Arp 220 are also detected in Zw Excited-OH absorptions in both galaxies display LTE, with the Zw line integrals ~12% the stronger. The HCN v 2 =1 absorption in Zw is a factor of ~2.5 times the weaker. In each of the two galaxies, the H 2 CO and CH 2 NH emission lines have similar relative strengths, with the absolute integrated luminosities of these lines being ~6 × stronger in Arp 220 than in Zw