J0423-0120 (PKS 0420-014) : The third stage of mm/sub-mm flare
ATel #14847; Seiji Kameno, Paulo Cortes, Edward Fomalont, Ruediger Kneissl, Antonio Hales, Celia Verdugo, Matias Radiszcz, Kurt Plarre, Cristian Lopez, Satoko Takahashi, Jose Fernandez, Jorge Garcia, Charles Hull, Pei-Ying Hsieh, Hugo Messias, David Rebolledo, Gabriel Marinello, Enrique Macias, Juan Cortes, Sergio Martin, Stuartt Corder (Joint ALMA Observatory), Claudia Agliozzo, Marie-Lou Gendron-Marsolais, Alvaro Ribas, Alejandro Santamaria, Chentao Yang, Eric Villard (European Southern Observatory), Brenda Matthews, Gerald Schieven (National Research Council Canada)
on 11 Aug 2021; 11:39 UT
Credential Certification: Seiji Kameno (seiji.kameno@alma.cl)
Subjects: Radio, Millimeter, Sub-Millimeter, AGN, Blazar, Quasar
Referred to by ATel #: 14889
The Atacama Large Millimeter/submillimeter Array (ALMA) has detected a radio flare of the quasar J0423-0120 (PKS 0420-014) at 97.5, 233, and 343.5 GHz. The total flux densities have started to increase since 2017 and reached September 2018 the first peak at 4.2 Jy, 2.8 Jy, and 2.6 Jy at 97.5, 233, and 343.5 GHz, respectively. After two years of plateau phase, the second flare must have arisen during the array shutdown between March 2020 and January 2021. The flux densities ascended to 5.2 Jy, 3.2 Jy, and 2.7 Jy at the restart of array operations in January to February 2021, and have peaked in April 2021 at 6.6 Jy, 4.4 Jy, and 3.8 Jy, respectively. The third flare has begun in June 2021 and reached the highest flux densities in ALMA monitoring at 7.62 +- 0.08 Jy, 4.97 +- 0.03 Jy, and 4.24 +- 0.05 Jy, respectively, on August 4-6, 2021.
Linearly polarized flux densities and polarization degrees in the second flare stage were 0.19 Jy (2.8 +- 0.5%), 0.12 Jy (2.7 +- 0.4%), and 0.22 Jy (5.7 +- 0.9%), and increased to 0.26 +- 0.06 Jy (3.4 +- 0.9%), 0.32 +- 0.02 Jy (6.5 +- 0.4%), and 0.35 +- 0.01 Jy (8.3 +- 0.3%), respectively, in the third stage. The electric-vector position angle (EVPA) of linear polarization was ~ -80 deg at the second flare stage and changed to -30 deg in the third stage.
See the detail of mm/sub-mm measurements: http://www.alma.cl/~skameno/AMAPOLA/J0423-0120.flux.html
See the detail of mm/sub-mm measurements
