Eta Carinae - The Dissipating Occulter Is an Extended StructureVisa övriga samt affilieringar
2023 (Engelska)Ingår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 954, nr 1, artikel-id 104Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
Previous Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) longslit observations of Eta Carinae (η Car) identified numerous absorption features in both the stellar spectrum, and in the adjacent nebular spectra, along our line of sight (LOS). The absorption features became temporarily stronger when the ionizing far-ultraviolet radiation field was reduced by the periastron passage of the secondary star. Subsequently, dissipation of a dusty structure in our LOS has led to a long-term increase in the apparent brightness of η Car, an increase in the ionizing ultraviolet (UV) radiation, and the disappearance of absorption from multiple velocity-separated shells extending across the foreground Homunculus lobe. We use HST/STIS spectro-images, coupled with published infrared and radio observations, to locate this intervening dusty structure. The velocity and spatial information indicate the occulter is ≈1000 au in front of η Car. The Homunculus is a transient structure composed of dusty, partially ionized ejecta that eventually will disappear due to the relentless rain of ionizing radiation and wind from the current binary system along with dissipation and mixing with the interstellar medium. This evolving complex continues to provide an astrophysical laboratory that changes on human timescales.
Ort, förlag, år, upplaga, sidor
Institute of Physics Publishing (IOPP), 2023. Vol. 954, nr 1, artikel-id 104
Nyckelord [en]
Massive stars, 732, Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Nationell ämneskategori
Astronomi, astrofysik och kosmologi
Identifikatorer
URN: urn:nbn:se:mau:diva-62850DOI: 10.3847/1538-4357/acdcf9ISI: 001054341100001Scopus ID: 2-s2.0-85170052156OAI: oai:DiVA.org:mau-62850DiVA, id: diva2:1800568
2023-09-272023-09-272023-10-10Bibliografiskt granskad