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SINCE THE VAST MAJORITY OF GALAXIES CONTAIN SUPERMASSIVE BLACK HOLES (SMBHS) AND GALAXY INTERACTIONS TRIGGER NUCLEAR GAS ACCRETION A DIRECT CONSEQUENCE OF THE HIERARCHICAL MODEL OF GALAXY FORMATION WOULD BE THE EXISTENCE OF DUAL ACTIVE GALACTIC NUCLEI (AGNS). BOTH THEORY AND OBSERVATIONS SUGGEST THAT MERGER TRIGGERED SMBH GROWTH PLAYS A VITAL ROLE IN DRIVING THE COORDINATED EVOLUTION OF SMBHS AND GALAXIES. DUAL AGNS WITH SEPARATIONS<10 KPC IN PARTICULAR PROVIDE UNAMBIGUOUS CONFIRMATION OF AN ONGOING MERGER AND ARE FOUND IN LATE STAGE MERGERS WHEN THE BLACK HOLES EXPERIENCE THEIR MOST RAPID GROWTH. DESPITE DECADES OF SEARCHING HOWEVER DUAL AGNS ARE EXTREMELY RARE AND MOST HAVE BEEN DISCOVERED SERENDIPITOUSLY. USING THE ALL-SKY WISE SURVEY WE IDENTIFIED A POPULATION OF ALMOST 200 STRONGLY INTERACTING GALAXIES THAT DISPLAY EXTREME RED MID-INFRARED COLORS (WL - W2>0.8) HIGHLY SUGGESTIVE OF POWERFUL AGNS. THE VAST MAJORITY OF THESE GALAXIES ARE OPTICALLY QUIESCENT SUGGESTING THAT THEY REPRESENT AN OBSCURED POPULATION OF AGNS THAT CANNOT BE FOUND THROUGH OPTICAL STUDIES. WE WERE RECENTLY AWARDED SHORT EXPOSURES BY CHANDRA TO OBSERVE THE 15 BRIGHTEST WISE-SELECTED DUAL AGN CANDIDATES WITH SEPARATIONS OF A FEW KILOPARSECS. OF THE 14 TARGETS OBSERVED THUS FAR 8 DISPLAY TWO NUCLEAR X-RAY POINT SOURCES AND NEAR-INFRARED SPECTRA SUGGESTIVE OF DUAL AGNS DESPITE HAVING NO OPTICAL SIGNATURES OF ACTIVITY DEMONSTRATING THAT 1) OPTICAL STUDIES MISS A SIGNIFICANT FRACTION OF DUAL AGNS AND 2) WISE PRE-SELECTION IS POTENTIALLY EXTREMELY EFFECTIVE IN IDENTIFYING THESE OBJECTS WHICH MAY REPRESENT THE MOST NUMEROUS POPULATION OF DUALS. WHILE THIS STUDY CAN POTENTIALLY EXPONENTIALLY INCREASE THE POPULATION OF DUALS IN ADVANCED MERGERS .AND REVOLUTIONIZE OUR UNDERSTANDING OF A KEY STAGE IN THE CO-EVAL EVOLUTION OF SMBHS AND GALAXIES THERE ARE INSUFFICIENT COUNTS IN OUR EXISTING OBSERVATIONS FOR A SPECTRAL ANALYSIS NECESSARY TO CONSTRAIN THE INTRINSIC ABSORPTION AND OBTAIN THE BOLOMETRIC LUMINOSITIES OF THE AGNS. WE PROPOSE TO FOLLOW-UP ON TWO OF THE BRIGHTEST TARGETS WITH XMM-NEWTON AND NUSTAR TO CONSTRAIN THE INTRINSIC ABSORPTION OF THE SYSTEMS AND CHARACTERIZE THE NATURE OF THE NUCLEAR SOURCE. THESE PROPOSED OBSERVATIONS ARE CRITICAL TO PROVIDE CONFIRMATION THAT THE EPOCH OF PEAK BLACK HOLE GROWTH IN MERGERS OCCURS IN A HIGHLY OBSCURED PHASE CONSISTENT WITH THEORETICAL PREDICTIONS. THIS PROGRAM IS COMPLEMENTARY TO OPTICAL SEARCHES AND WILL BE THE FIRST DETAILED INVESTIGATION INTO THE PHYSICAL ENVIRONMENT OF THESE OPTICALLY OBSCURED DUAL AGNS.

$47,853FY2020National Aeronautics and Space AdministrationNASA

George Mason University, Fairfax VA

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