Sub-arcsecond imaging of Arp 299-A at 150 MHz with LOFAR: Evidence for a starburst-driven outflow

Ramírez-Olivencia, N. ; Varenius, E. ; Pérez-Torres, M. (Universidad de Zaragoza) ; Alberdi, A. ; Pérez, E. ; Alonso-Herrero, A. ; Deller, A. ; Herrero-Illana, R. ; Moldón, J. ; Barcos-Muñoz, L. ; Martí-Vidal, I.

Resumen: We report on the first sub-arcsecond (0.44 × 0.41 arcsec2) angular resolution image at 150 MHz of the A-nucleus in the luminous infrared galaxy Arp 299, from International Low Frequency Array (LOFAR) Telescope observations. The most remarkable finding is that of an intriguing two-sided, filamentary structure emanating from the A-nucleus, which we interpret as an outflow that extends up to at least 14 arcsec from the A-nucleus in the N-S direction (˜5 kpc deprojected size) and accounts for almost 40% of the extended emission of the entire galaxy system. We also discuss HST/NICMOS [FeII] 1.64 µm and H2 2.12 µm images of Arp 299-A, which show similar features to those unveiled by our 150 MHz LOFAR observations, providing strong morphological support for the outflow scenario. Finally, we discuss unpublished Na I D spectra that confirm the outflow nature of this structure. From energetic arguments, we rule out the low-luminosity active galactic nucleus in Arp 299-A as a driver for the outflow. On the contrary, the powerful, compact starburst in the central regions of Arp 299-A provides plenty of mechanical energy to sustain an outflow, and we conclude that the intense supernova (SN) activity in the nuclear region of Arp 299-A is driving the observed outflow. We estimate that the starburst wind can support a mass-outflow rate in the range (11-63 M¿ yr-1) at speeds of up to 370-890 km s-1, and is relatively young, with an estimated kinematic age of 3-7 Myr. Those results open an avenue to the use of low-frequency (150 MHz), sub-arcsecond imaging with LOFAR to detect outflows in the central regions of local luminous infrared galaxies.

Idioma: Inglés

DOI: 10.1051/0004-6361/201732543

Año: 2018

Publicado en: Astronomy & astrophysics 610 (2018), L18 [7 pp]
ISSN: 0004-6361

Factor impacto JCR: 6.209 (2018)

Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 10 / 69 = 0.145 (2018) - Q1 - T1

Factor impacto SCIMAGO: 2.527 - Space and Planetary Science (Q1) - Astronomy and Astrophysics (Q1)

Tipo y forma: (Versión definitiva)

Área (Departamento): Área Física Teórica (Dpto. Física Teórica)