Disentangling the nature of the first radio weak BL Lac: Contemporaneous multifrequency observations of WISE J141046.00+740511.2

EZEQUIEL MARCHESINI; VICTORIA REYNALDI; FLORENCIA VIEYRO; JULIANA SAPONARA; ILEANA ANDRUCHOW; IVÁN LÓPEZ; PAULA BENAGLIA; SERGIO CELLONE; NICOLA MASETTI; FRANCESCO MASSARO; HAROLD A. PEÑA HERAZO; VAHARAM CHAVUSHYAN; JORGE A. COMBI; JOSÉ A. ACOSTA-PULIDO; BEATRIZ AGÍS GONZÁLEZ; NOEL CASTRO SEGURA

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2023 vol. 670

0004-6361

Context. The γ-ray emitting source WISE J141046.00+740511.2 was associated to a Fermi-LAT detection by crossmatching withSwift/XRT data. It has shown all canonical observational characteristics of a BL Lac source, including a power-law, featurelessoptical spectrum. But it was only recently detected at radio frequencies, and its radio flux is significantly low.Aims. Given that a radio detection is fundamental to associate lower-energy counterparts to Fermi-LAT sources, we aim to unambigu-ously classify this source by performing a multiwavelength analysis with contemporaneous data.Methods. By using multifrequency observations at the Jansky Very Large Array, Giant Metrewave Radio Telescope, Gran Telesco-pio Canarias, Gemini, William Herschel Telescope and Liverpool observatories, and together with Fermi-LAT and Swift data, wehave carried out two kinds of analysis. On one hand, we have studied several known parameters that account for the radio loud-ness/weakness characterization and their application to blazars (in general) and to our source (in particular). And, on the other hand,we built and analyzed the observed spectral energy distribution (SED) of this source to try to explain its peculiar characteristics.Results. The multiwavelength analysis indicates that WISE J141046.00+740511.2 is a blazar of the high-frequency peaked (HBL)type, that emits highly polarized light and that is likely located at low redshift. In addition, the one-zone model parameters that bestfit its SED are those of an extreme HBL (EHBL), which have been long predicted in theory to lack the radio emission typical ofcanonical γ-ray blazars.Conclusions. We confirm that WISE J141046.00+740511.2 is indeed a highly polarized BL Lac of the HBL type. Further studieswill be conducted in other to explain the atypical low radio flux detected from this source