Molecular Line Measurements of Luminous Infrared Galaxies (LIRGs) AO 4 David Cotten Alexandre Roman-Lopes Carol Lonsdale Ximena Fernandez Advisor: Chris Salter Gas is turning into stars extremely rapidly with its circumnuclear volume. The dust heating associated with these intense bursts of star formation produce a large increase in IR luminosity and favorable conditions for radio maser emission.

Luminous Infrared Galaxies (LIRGs) Emit most of the energy in the infrared Lir > 1011 L Found in interacting/merging systems ULIRGs: Lir > 1012 L Mostly advanced mergers

Arp 220 λ6 cm excited OH transitions HCN Methanol Methanimine Prototype of this type of system. It has twin nuclei, strong OH maser emission, and 21-cm line absorption. Salter et al. 2008

Observing Targets IC 860 Zw049.057 z=0.012943 log(Lir )=10.78

Spectral Line Observations L-Band Wide Receiver (1.15-1.75 GHz) Wideband Arecibo Pulsar Processor (WAPP) Spectrometer HI Line: 1420 Mhz OH main-line: 1665-MHz OH main-line: 1667-MHz OH satellite line: 1612-MHz OH satellite line: 1720-MHz OH main-lines: 1637 & 1639 MHz, Formic Acid:1638 MHz HCN line: 1346 MHz HCO+ line: 1270 MHz Observing technique: Double Position Switching (DPS)

IC860 IC860 OH main-lines: 1665 & 1667-MHz HI Line OH satellite lines: 1612 & 1720-MHz OH main-lines: 1637 & 1639 MHz, Formic Acid:1639 MHz HI lines 1665 1667 OH main line HCN line: 1346 MHz HCO+ line: 1270 MHz

Zw049.057 OH main-lines: 1665 & 1667-MHz HI Line OH satellite lines: 1612 & 1720-MHz OH main-lines: 1637 & 1639 MHz, Formic Acid:1639 MHz HI lines 1665 1667 OH main line HCN line: 1346 MHz HCO+ line: 1270 MHz

New detection of the Satellite Lines in Zw049.057! Both lines have conjugate behavior: two transitions competing for the same pumping photons

Estimates for Column Density