# # Program information file # PROGRAM_ID 2024B040 PROGRAM_TITLE Unveiling the Enigmatic Double-Peaked Mysteries: Probing Accretion Disk Outskirts in AGNs Through Multiwavelength Analysis PROGRAM_INV1 Swayamtrupta Panda PROGRAM_INV2 Denimara Dias dos Santos PROGRAM_INV3 Alberto Rodriguez Ardila PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT extra-galactic PROGRAM_ABSTRACT_BEG Active galactic nuclei [AGNs] Type-I spectra often exhibit broad emission lines, with a subset displaying double-peaked profiles indicative of a broad line region [BLR] with a disk-like structure. Recent observations in the near-infrared [NIR] have confirmed double-peaked emission lines in AGNs like III Zw 002, shedding light on BLR geometry and kinematics. We aim to explore the periphery of AGN accretion disks using NIR emission lines, such as singly ionized oxygen, and Paschen lines, and estimate accretion disk properties, including inclination and radial extension, and study the variations of this special class of AGNs along the quasar main sequence. We request IRTF/SpeX spectroscopy in SXD mode for 14 double-peak AGN candidates that, have archival SDSS spectroscopy, and are suitable for the 2024B semester. Through this proposal, we will procure the NIR spectra for our targets for the first time and complement them with existing optical spectroscopy. The added advantage of analyzing the emission lines in the NIR is that they are isolated or semi-isolated, in contrast to their optical counterparts, and thereby, provide better constraints on the fitted parameters from the accretion disk model. This comprehensive approach is crucial for deciphering the complex interplay between accretion disk geometry, kinematics of the disk and the BLR, and the central supermassive black hole environment, contributing to a deeper understanding of AGN phenomena. These new observations will allow us to estimate the accretion disk's inclination and hence, the black hole masses in these objects, and put constraints on the outer edge of the accretion disk in this fascinating class of AGNs. PROGRAM_ABSTRACT_END