@misc{10481/112069,
year = {2026},
month = {2},
url = {https://hdl.handle.net/10481/112069},
abstract = {LHAASO J2108 + 5157 is one of the few ultra-high energy γ-ray sources in the LHAASO catalogue without secure counter- part at longer wav elengths. Several Galactic scenarios have been proposed, including an evolved supernova remnant and a pulsar wind nebula. Yet, no shocked gas, shell-like structure, or compact pulsar candidate has been identified. Follow-up observations with VERITAS and the LST-1 prototype have not firmly clarified its nature. A recent microquasar candidate from GMRT radio data remains uncertain. Here, we present the first dedicated near-infrared study of the field, combining deep JHKs imaging with narrow band observations targeting the H 2 v = 1–0 S(1) line. Our observations were initially planned to encompass the full source region, but now only partially cover the latest updated position and size of LHAASO J2108 + 5157. We find no evidence of shocked emission, extended nebular structures, or an accreting compact object signature in the covered field. The GMRT radio source, despite its jet-like morphology, exhibits near-infrared properties incompatible with both a Galactic microquasar and a nearby radio galaxy, discouraging an association with the gamma-ray emission. Our analysis reveals no convincing counterpart within the positional uncertainty, leaving LHAASO J2108 + 5157 as an enigmatic ultra-high energy emitter that requires deeper observations.},
organization = {MCIN/AEI/10.13039/501100011033 and ‘ERDF A way of making Europe - (PID2022-136828NB-C41) (PID2022-136828NB-C42)},
organization = {Institute of Cosmos Sciences - (CEX2024- 001451-M)},
organization = {NextGenerationEU funds - (AS T22_0001_16)},
publisher = {Royal Astronomical Society},
keywords = {Gamma-rays: general},
keywords = {Radio continuum: galaxies},
keywords = {X-rays: binaries},
title = {Unmasking  LHAASO  J2108  +  5157:  near-infrared  insights  into  a  mysterious  TeV  source},
doi = {10.1093/mnras/stag297},
author = {Martí, Josep and Luque Escamilla, Pedro L. and Paredes, Josep M. and Martínez Aroza, José Antonio},
}