TY - JOUR
T1 - Nebular C iv λ1550 Imaging of the Metal-poor Starburst Mrk 71
T2 - Direct Evidence of Catastrophic Cooling
AU - Oey, M. S.
AU - Sawant, Amit N.
AU - Danehkar, Ashkbiz
AU - Silich, Sergiy
AU - Smith, Linda J.
AU - Melinder, Jens
AU - Leitherer, Claus
AU - Hayes, Matthew
AU - Jaskot, Anne E.
AU - Calzetti, Daniela
AU - Chu, You Hua
AU - James, Bethan L.
AU - Östlin, Göran
N1 - We thank Will Gray, Genoveva Micheva, and Megan Reiter for useful discussions, and Roberto Avila of the STScI Astrodrizzle team for advice on the drizzle procedure. We also thank the anonymous referee for useful comments and questions. This work was supported by NASA HST-GO-16261. S.S. is supported by CONAHCYT, México, research grant A1-S-28458. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. These observations are associated with program 16261. The data presented in this Letter were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi: 10.17909/90na-ch15 .
PY - 2023/11/1
Y1 - 2023/11/1
N2 - We use the Hubble Space Telescope Advanced Camera for Surveys to obtain the first spatially resolved, nebular imaging in the light of C iv λ λ1548, 1551 by using the F150LP and F165LP filters. These observations of the local starburst Mrk 71 in NGC 2366 show emission apparently originating within the interior cavity around the dominant super star cluster (SSC), Knot A. Together with imaging in He ii λ4686 and supporting Space Telescope Imaging Spectrograph far-ultraviolet spectroscopy, the morphology and intensity of the C iv nebular surface brightness and the C iv/He ii ratio map provide direct evidence that the mechanical feedback is likely dominated by catastrophic radiative cooling, which strongly disrupts adiabatic superbubble evolution. The implied extreme mass loading and low kinetic efficiency of the cluster wind are reasonably consistent with the wind energy budget, which is probably enhanced by radiation pressure. In contrast, the Knot B SSC lies within a well-defined superbubble with associated soft X-rays and He ii λ1640 emission, which are signatures of adiabatic, energy-driven feedback from a supernova-driven outflow. This system lacks clear evidence of C iv from the limb-brightened shell, as expected for this model, but the observations may not be deep enough to confirm its presence. We also detect a small C iv-emitting object that is likely an embedded compact H ii region. Its C iv emission may indicate the presence of very massive stars (>100 M ⊙) or strongly pressure-confined stellar feedback.
AB - We use the Hubble Space Telescope Advanced Camera for Surveys to obtain the first spatially resolved, nebular imaging in the light of C iv λ λ1548, 1551 by using the F150LP and F165LP filters. These observations of the local starburst Mrk 71 in NGC 2366 show emission apparently originating within the interior cavity around the dominant super star cluster (SSC), Knot A. Together with imaging in He ii λ4686 and supporting Space Telescope Imaging Spectrograph far-ultraviolet spectroscopy, the morphology and intensity of the C iv nebular surface brightness and the C iv/He ii ratio map provide direct evidence that the mechanical feedback is likely dominated by catastrophic radiative cooling, which strongly disrupts adiabatic superbubble evolution. The implied extreme mass loading and low kinetic efficiency of the cluster wind are reasonably consistent with the wind energy budget, which is probably enhanced by radiation pressure. In contrast, the Knot B SSC lies within a well-defined superbubble with associated soft X-rays and He ii λ1640 emission, which are signatures of adiabatic, energy-driven feedback from a supernova-driven outflow. This system lacks clear evidence of C iv from the limb-brightened shell, as expected for this model, but the observations may not be deep enough to confirm its presence. We also detect a small C iv-emitting object that is likely an embedded compact H ii region. Its C iv emission may indicate the presence of very massive stars (>100 M ⊙) or strongly pressure-confined stellar feedback.
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U2 - 10.3847/2041-8213/ad07dd
DO - 10.3847/2041-8213/ad07dd
M3 - Article
AN - SCOPUS:85177744634
SN - 2041-8205
VL - 1
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - L10
M1 - L10
ER -