The population of compact radio sources in M 17

• Published in: arXiv.org 2022-04
• Main Authors: Yanza, Vanessa, Masqué, Josep M, Dzib, Sergio A, Rodríguez, Luis F, Medina, S -N X, Kurtz, Stan, Loinard, Laurent, Trinidad, Miguel A, Menten, Karl M, Rodríguez-Rico, Carlos A
• Format: Article
• Language: English
• Subjects: Comets; Emission; Luminosity; Massive stars; Orion nebula; Protostars; Radio; Radio observation; Radio sources (astronomy); Spatial distribution; Stellar coronas; Superhigh frequencies
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2204.09555

We present a catalog of radio sources of the M 17 region based on deep X band radio observations centered at 10 GHz obtained with the Jansky Very Large Array in the A configuration. We detect a total of 194 radio sources, 12 of them extended and 182 compact. We find that a significant fraction (at least 40% in our catalog) have suspected gyrosynchrotron emission associated with stellar coronal emission. By comparing the radio luminosities of our sources with their X ray counterparts, when available, we find that they are underluminous in X rays with respect to the G\"udel Benz relation, but a correlation with a similar slope is obtained provided that only sources with evident non thermal nature are selected from the sample compiled for the Orion Nebula Cluster (ONC) and M 17. The comparison of M 17 with the ONC and NGC 6334D-F leads to a similar luminosity function for the three regions, at least for the more luminous sources. However, the radio sources in M 17 are three times more numerous compared to the other regions at a given luminosity and their spatial distribution differs from that of Orion. Moreover, an arc-shaped structure of 40\("\) in extent is observed in our map, identified previously as an ionizing front, with the cometary Hyper Compact source UC1 at its focus. Archival 1 mm ALMA data reveals compact emission coincident with the radio wavelength peak, possibly associated with a protostellar disk of the massive star exciting UC1.