Year: 2024
Type: article
Abstract: The late-stage galaxy merger and prototypical ultraluminous infrared galaxy (ULIRG) Arp 220 is probed using the JWST Mid Infrared Instrument medium-resolution spectrometer to search for multiple diagnostic active galactic nuclei (AGN) emission lines in the low-interstellar-opacity spectral ranges of 5.3–7.9 μm and 12.9–16.0 μm. We detect none of the characteristic high-excitation AGN emission lines. The most diagnostic nondetections are of the [Ne vi] λ 7.652 μm and [Ne v] λ 14.32 μm lines, for which the combined upper limit is ∼10–20 times fainter than the equivalent limit from Spitzer data. We also use X-ray measurements of the reflected Fe Kα line to suggest a relatively low X-ray luminosity. These results suggest that the high obscuration observed along the line of sight to the nuclei of Arp 220 is isotropic and keeps any high-excitation emission from a putative AGN from escaping. An implication is that the observed mid-infrared output of the nuclei is essentially their bolometric luminosity, i.e., no significant additional energy escapes. We utilize this result to show that any embedded AGNs are accreting at no more than ∼5% of the Eddington rate, lower than many theoretical predictions for this stage of ULIRG evolution.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Aeronautics and Space Administration, University of Arizona, European Commission, Nuclear Safety and Security Commission, Goddard Space Flight Center, European Regional Development Fund, Agencia Estatal de Investigación, Astrophysics Science Division, HORIZON EUROPE European Research Council
Awards: G1175115578, G1632446036, G210041235, G2114305129, G2262748287, G2601397997, G300979063, G34346518, G3480869486, G3681454997, G4042783231, G410571670, G425668148, G451917667, G4719436119, G5080475149, G5677826004, G5967599077, 1. SCIENCE INVESTIGATION: SUMMARY IN MY ORIGINAL PROPOSAL WRITTEN PRIOR TO THE LAUNCH OF SPITZER I PLANNED A JWST PROGRAM ON ACTIVE GALACTIC NUCLEI (AGN) AND THEIR HOST GALAXIES BUILDING ON THEN-FUTURE SPITZER OBSERVATIONS. TOWARD THE END OF THE SPITZER COLD MISSION AS THE PI FOR THE MIPS INSTRUMENT I HAD LED SUBSTANTIAL PROGRAMS ON BOTH EXTRAGALACTIC OBSERVATIONS AND DEBRIS DISKS SO I PROPOSED TO EXPAND MY JWST EFFORT TO INCLUDE BOTH AN EXPANSION THAT WAS APPROVED BY ED WEILER ON OCTOBER 16 2009. THE FOLLOWING PROGRAM THEREFORE INCLUDES BOTH OF THESE THEMES. SINCE BOTH PROPOSALS WERE WRITTEN MAJOR NEW CAPABILITIES HAVE ANSWERED SOME OF THE PREVIOUS SCIENTIFIC QUESTIONS AND POSED NEW ONES. IN THE EXTRAGALACTIC ARENA THESE INCLUDE SPITZER ITSELF HERSCHEL THE EXPANDED CAPABILITIES OF THE JVLA AND ALMA. FOR DEBRIS DISKS THE MOST IMPORTANT ARE HERSCHEL ALMA AND HIGH PERFORMANCE ADAPTIVE OPTICS. THEREFORE THE MATERIAL IN THIS PROPOSAL IS RE-THOUGHT TO PROVIDE A PROGRAM AT THE CUTTING EDGE OF THE CURRENT PROBLEMS IN THESE AREAS. EACH OF THE INDIVIDUAL INVESTIGATIONS DESCRIBED BELOW IS DESCRIBED IN A DETAILED INTERNAL REPORT AND IS READY FOR DETAILED OBSERVATION PLANNING. THIS PROPOSAL GIVES A SUMMARY OF THE HIGH LEVEL GOALS AND REQUIRED OBSERVATIONS ONLY. IT INTENTIONALLY SOMEWHAT OVERSUBSCRIBES MY TIME ALLOTMENT TO ALLOW FOR COLLABORATIONS AND SHARED TIME AS WELL AS FURTHER OPTIMIZATION. ALTHOUGH THERE ARE A NUMBER OF INVESTIGATIONS MY RESEARCH GROUP HAS BEEN ACTIVE IN ALL OF THEM; I HAVE BOLD-FACED CITATIONS OF OUR RELEVANT WORK IN THE BIBLIOGRAPHY (ATTACHED AS APPENDIX A). IN ADDITION I WAS ASSIGNED AN ADDITIONAL 60 HOURS OF GTO TIME TO BE DISTRIBUTED AMONG (MOSTLY) YOUNG SCIENTISTS IN THE UNITED STATES WHO HAD MADE MAJOR COMMITMENTS IN SUPPORT OF MIRI (ROUGHLY PARALLEL TO THE GTO TIME FOR MIRI SUPPORT BY THE EUROPEAN CONSORTIUM (EC)). APPENDIX C INCLUDES SHORT STATUS REPORTS ON THEIR PLANS., G7434936867, G7642730041, Black hOle Optical-polarization TimE-domain Survey, G8156742736, G929308097
OpenAlex ID: W4404927245