The Nature of the Ultraluminous Oxygen-Rich Supernova Remnant in NGC 4449

Abstract

Optical images and spectra, both ground based and taken by Hubble Space Telescope (HST), of the young, luminous O-rich supernova remnant in the irregular galaxy NGC 4449 are presented. HST images of the remnant and its local region were obtained with the ACS/WFC using filters F435W, F555W, F814W (B, V, and I, respectively), F502N ([O III]), F658N (Halpha + [N II]), F660N ([N II]), and F550M (line-free continuum). These images show an unresolved remnant (FWHM < 0.05 arcsec) located within a rich cluster of OB stars which itself is enclosed by a nearly complete interstellar shell seen best in Halpha + [N II] emission approximately 8'' x 6'' (150 pc x 110 pc) in size. The remnant and its associated OB cluster are isolated from two large nearby H II regions. The ACS [O III] image shows the remnant may be partially surrounded by a clumpy ring of emission approximately 1'' (~20 pc) in diameter. Recent ground-based spectra of the remnant reveal (1) the emergence of broad, blueshifted emission lines of [S II] 6716, 6731, [Ar III] 7136, and [Ca II] 7291, 7324 which were not observed in spectra taken in 1978 -- 1980; (2) faint emission at 6540 -- 6605 A centered about Halpha and [N II] 6548, 6583 with an expansion velocity of 500 +/- 100 km/s; and (3) excess emission around 4600 -- 4700 A suggestive of a Wolf-Rayet population in the remnant's star cluster. We use these new data to re-interpret the origin of the remnant's prolonged and bright luminosity and propose that the remnant is strongly interacting with dense, circumstellar wind loss material from a ~20 Msolar progenitor star.

arXiv comment20 pages, 10 figures. Matches version published in ApJ

References in corpus (14)

• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• WFPC2 Stellar Photometry with HSTphot
• Stellar evolution with rotation VII: Low metallicity models and the blue to red supergiant ratio in the SMC
• On the progenitor of SN 2005gl and the nature of Type IIn supernovae
• The Expansion Center and Dynamical Age of the Galactic Supernova Remnant Cassiopeia A
• Constraints on the Progenitor of Cassiopeia A
• The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turn-offs. I. Results from 19 OB Associations in the Magellanic Clouds
• Late-Time Optical and UV Spectra of SN 1979C and SN 1980K
• Chandra Observation of NGC4449. Analysis of the X-ray Emission from a Dwarf Starburst Galaxy
• Modelling the Hubble Space Telescope Ultraviolet and Optical Spectrum of Spot 1 on the Circumstellar Ring of SN 1987A
• Hot Interstellar Gas in the Irregular Galaxy NGC 4449
• Physical Structure of Small Wolf-Rayet Ring Nebulae
• Chandra Observations of the Luminous, O-Rich SNR in the Irregular Galaxy NGC 4449
• VLA Observations of J1228+441, a Luminous Supernova Remnant in NGC 4449

Cited by in corpus (17)

• Toward a Unification of Star Formation Rate Determinations in the Milky Way and Other Galaxies
• Late-Time Optical Emission From Core-Collapse Supernovae
• PS1-14bj: A Hydrogen-Poor Superluminous Supernova With a Long Rise and Slow Decay
• Detection of a High Brightness Temperature Radio Core in the AGN-Driven Molecular Outflow Candidate NGC 1266
• A GMOS-N IFU study of the central H II region in the blue compact dwarf galaxy NGC 4449: Kinematics, Nebular Metallicity and Star-Formation
• A New, Larger Sample of Supernova Remnants in NGC 6946
• A Search for Radio Supernova Remnants in Four Irregular Galaxies
• The Supernova -- Supernova Remnant Connection
• A Spectroscopic Study of the Rich Supernova Remnant Population in M83
• Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us
• A Newly Recognized Very Young Supernova Remnant in M83
• The First VLBI Image of the Young, Oxygen-Rich Supernova Remnant in NGC 4449
• Spitzer Spectroscopy of the Galactic Supernova Remnant G292.0+1.8: Structure and Composition of the Oxygen-Rich Ejecta
• The resolved structure of the extragalactic supernova remnant SNR 4449-1
• Kinematics of Supernova Remnants: Status of X-Ray Observations
• Detection of Late-Time Optical Emission from SN 1941C in NGC 4136
• Discovery of young, oxygen-rich supernova remnants in PHANGS-MUSE galaxies