对超新星（SNe）前身星的搜寻一直依赖于在偶然获得的爆前图像中直接探测到该恒星。我们提出一种替代方法，将恒星光度种群拟合与电离气体的积分场单元（IFU）光谱分析相结合，以全面探索超新星环境并约束前身星性质。对 HST/WFC3 观测的等时线拟合表明，iPTF13bvn 的环境包含两个具有独特年龄（τ=log t [年]）和消光（A_V）值的恒星种群；以往关于 iPTF13bvn 前身星的研究与我们最老的恒星种群（P2）之间符合得最好：τ_P2=6.97^{+0.06}_{-0.06}，相应的初始质量 M_initial,P2=20.0 M⊙，且 A_V,P2=0.53^{+0.10}_{-0.08} 星等。利用 VLT/MUSE IFU 光谱观测开展的进一步分析显示，不存在与 iPTF13bvn 相关的明亮 H II 区，表明其附近没有正在进行的恒星形成。由电离气体导出的消光至少比已分辨恒星种群的值高约 2.5 倍，这有助于构建该环境的三维图像。对视点（spaxel）消光分布的分析表明，位于一条旋臂边缘的 iPTF13bvn 环境具有更强的变化性。我们的研究突显了恒星、气体和尘埃之间的复杂关系，以及在整体环境分析中综合利用它们时，如何能够开始解决长期困扰以往前身星研究的简并问题。具体到 iPTF13bvn，我们的结果支持双星前身星，并支持日益形成的共识：双星性是 Ib 型超新星前身星的主要质量损失机制。
英文摘要：
Searches for supernovae (SNe) progenitors have relied on a direct detection of the star in fortuitous pre-explosion images. We propose an alternative method, using a combination of photometric stellar population fitting alongside integral-field-unit (IFU) spectroscopic analysis of the ionised gas to fully explore the SN environment and constrain the progenitor properties. Isochrone fitting of HST/WFC3 observations reveals the environment of iPTF13bvn contains two stellar populations with unique age ($τ=\log{t [years]}$) and extinction ($A_V$) values, with the closest agreement found between past progenitor studies of iPTF13bvn and our oldest stellar population (P2): $τ_{P2}=6.97^{+0.06}_{-0.06}$, a corresponding initial mass $M_{initial,P2} = 20.0 M_\odot$ and $A_{V,P2}=0.53^{+0.10}_{-0.08}$ mag. Further analysis with VLT/MUSE IFU-spectroscopic observations reveals no bright H II regions associated with iPTF13bvn, suggesting no immediate ongoing star formation. Extinctions derived from the ionised gas are a minimum of ~2.5 times higher than the resolved stellar population values, assisting in building a 3D picture of the environment. An analysis of the distribution of spaxel extinctions reveals increased variability in the environment of iPTF13bvn, on the edge of a spiral arm. Our study highlights the complex relationship between stars, gas and dust and how, when used in a holistic environmental analysis, they can begin to resolve degeneracies that have plagued past progenitor investigations. Specifically for iPTF13bvn, our results support a binary progenitor and a growing consensus for binarity as the predominant mass-loss mechanism for Type Ib SNe progenitors.
We present a statistical analysis of the environments of 11 supernovae (SNe) which occurred in 6 nearby galaxies (z $\lesssim$ 0.016). All galaxies were observed with MUSE, the high spatial resolution integral field spectrograph mounted to the 8m VLT UT4. These data enable us to map the full spatial extent of host galaxies up to $\sim$3 effective radii. In this way, not only can one characterise the specific host environment of each SN, one can compare their properties with stellar populations within the full range of other environments within the host. We present a method that consists of sel…
Here we describe a new study of the SNRs and SNR candidates in nearby face-on spiral galaxy M83, based primarily on MUSE integral field spectroscopy. Our revised catalog of SNR candidates in M83 has 366 objects, 81 of which are reported here for the first time. Of these, 229 lie within the MUSE observation region, 160 of which have spectra with [SII]:Halpha ratios exceeding 0.4, the value generally accepted as confirmation that an emission nebula is shock-heated. Combined with 51 SNR candidates outside the MUSE region with high [SII]:Halpha ratios, there are 211 spectroscopically-confirmed SNR…
A statistical study of the environmental age of core-collapse supernovae based on VLT/MUSE integral-field-unit spectroscopy
University of Chinese Academy of Sciences（中国科学院大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；National and Kapodistrian University of Athens（雅典国立卡波迪斯特里阿斯大学）；Foundation for Research and Technology-Hellas（希腊研究与技术基金会）；School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）
NGC6946 is a high star formation rate face-on spiral galaxy that has hosted ten supernovae since 1917. Not surprisingly, a large number of supernova remnants and candidates have been identified either as optical nebulae with high [S II]:H$α$ line ratios (147) or as compact non-thermal radio sources (35). However, there are only seven overlaps between these two samples. Here, we apply [Fe II] 1.644 $μ$m emission as a new diagnostic to search for supernova remnants in an attempt to resolve this discrepancy. [Fe II] is expected to be relatively strong in the radiative shocks of supernova remnants…
The local ultraviolet signature of Type Ia supernova environments from HST and MUSE
Institute of Space Sciences (ICE-CSIC)（空间科学研究所）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚太空研究学院）；Department of Physics and Astronomy and PITT PACC, University of Pittsburgh（匹兹堡大学物理与天文系及PITT PACC）；European Southern Observatory（欧洲南方天文台）；Departamento de Física Teórica, Universidad Autónoma de Madrid (UAM)（马德里自治大学理论物理系）；Centro de Investigación Avanzada en Física Fundamental (CIAFF-UAM)（基础物理高级研究中心）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天文学研究所）；Las Campanas Observatory, Carnegie Observatories（拉斯坎帕纳斯天文台，卡内基观测站）
SN 2002cx-like Type Ia supernovae (also known as SNe Iax) represent one of the most numerous peculiar SN classes. They differ from normal SNe Ia by having fainter peak magnitudes, faster decline rates and lower photospheric velocities, displaying a wide diversity in these properties. We present both integral-field and long-slit visual-wavelength spectroscopy of the host galaxies and explosion sites of SNe Iax to provide constraints on their progenitor formation scenarios. The SN Iax explosion site metallicity distribution is similar to that of core-collapse (CC) SNe and metal-poor compared to …
AT 2018cow was the nearest and best studied example of a new breed of extra-galactic, luminous and rapidly-evolving transient. Both the progenitor systems and explosion mechanisms of these rapid transients remain a mystery - the energetics, spectral signatures, and timescales make them challenging to interpret in established classes of supernovae and tidal disruption events. The rich, multi-wavelength data-set of AT 2018cow has still left several interpretations viable to explain the nature of this event. In this paper we analyse integral-field spectroscopic data of the host galaxy, CGCG 137-0…
A MUSE View of the Optical Torus within the Supernova Remnant 1E 0102.2-7219
The University of Manitoba（曼尼托巴大学）；Australian National University（澳大利亚国立大学）；Federal Office of Meteorology and Climatology – MeteoSwiss（瑞士联邦气象和气候局）；Towson University（陶森大学）；National Chengchi University（国立政治大学）；Mathematical Sciences Institute, The Australian National University（澳大利亚国立大学数学科学研究所）
We present pre-explosion photometry of the likely progenitor star of the Type II supernova (SN II) 2017eaw in NGC 6946. We use a Hubble Space Telescope (HST) image of SN 2017eaw to perform relative astrometry with HST and Spitzer Space Telescope (Spitzer) imaging, finding a single point source consistent with its position. We detect the progenitor star in $>$40 epochs of HST and Spitzer imaging covering 12.9 years to 43 days before discovery. While the progenitor luminosity was roughly constant for most of this period, there was a $\sim$20% increase in its $4.5~μ$m luminosity over the final 3 …
We present a detection in pre-explosion Hubble Space Telescope (HST) imaging of a point source consistent with being the progenitor star of the Type IIb supernova (SN IIb) 2016gkg. Post-explosion imaging from the Keck Adaptive Optics system was used to perform relative astrometry between the Keck and HST imaging. We identify a single point source in the HST images coincident with the SN position to 0.89-sigma. The HST photometry is consistent with the progenitor star being an A0Ia star with T=9500 K and log (L/Lsun)=5.15. We find that the SN 2016gkg progenitor star appears more consistent with…
Short-GRB progenitors could come in various flavors, depending on the nature of the merging compact stellar objects (including a stellar-mass black hole or not) or depending on their ages (millions or billions of years). At a redshift of z=0.122, the nearly face-on spiral host of the short GRB 080905A is one of the closest short-GRB host galaxies identified so far. This made it a preferred target to explore spatially resolved star-formation and to investigate the afterglow position in the context of its star formation structures. We used VLT/MUSE integral-field unit observations, supplemented …
We present MUSE observations of galaxy NGC 7469 from its Science Verification to show how powerful is the combination of high-resolution wide-field integral field spectroscopy with both photometric and spectroscopic observations of supernova (SN) explosions. Using STARLIGHT and HIIexplorer, we selected all Hii regions of the galaxy and produced 2- dimensional maps of the Hα equivalent width, average luminosity-weighted stellar age, and oxygen abundance. We measured deprojected galactocentric distances for all Hii regions, and radial gradients for all above-mentioned parameters. We positioned t…
The presence of large ionised gaseous nebulae found around some ultraluminous X-ray sources (ULXs) provides the means to assess the mechanical and radiative feedback of the central source, and hence constrain the efficiency and impact on the surroundings of the super-Eddington regime powering most of these sources. NGC 1313 X--1 is an archetypal ULX which has been reported to be surrounded by abnormally high [O I]$λ$6300/H$α>$ 0.1 ratios and for which high-resolution spectroscopy in X-rays has hinted the presence of powerful outflows. We report observations taken with the Multi-Unit Spectrosco…
We present Hubble Space Telescope (HST) rest-frame ultraviolet imaging of the host galaxies of 16 hydrogen-poor superluminous supernovae (SLSNe), including 11 events from the Pan-STARRS Medium Deep Survey. Taking advantage of the superb angular resolution of HST, we characterize the galaxies' morphological properties, sizes and star formation rate (SFR) densities. We determine the supernova (SN) locations within the host galaxies through precise astrometric matching, and measure physical and host-normalized offsets, as well as the SN positions within the cumulative distribution of UV light pix…
We present the delay time distribution (DTD) estimates of Type Ia supernovae (SNe~Ia) using spatially resolved SN~Ia host galaxy spectra from MUSE and MaNGA. By employing a grouping algorithm based on k-means and earth mover's distances (EMD), we separated the host galaxy star formation histories (SFHs) into spatially distinct regions and used maximum likelihood method to constrain the DTD of SNe Ia progenitors. When a power-law model of the form $DTD(t)\propto t^{s} (t>τ)$ is used, we found an SN rate decay slope $s=-1.41^{+0.32}_{-0.33}$ and a delay time $τ=120^{+142}_{-83} Myr$ . Moreover, …
We present optical photometry and spectroscopy of the Type II supernova ASASSN-14jb, together with VLT MUSE IFU observations of its host galaxy and a nebular-phase spectrum. This SN, in the nearby galaxy ESO 467-G051 ($z=0.006$), was discovered and followed-up by the All Sky Automated Survey for SuperNovae (ASAS-SN). We present LCOGTN $BVgri$ and $Swift$ $w2m1w1ubv$ optical and near-UV/optical light curves and several optical spectra in the early photospheric phase. ASASSN-14jb exploded $\sim 2$ kpc above the star-forming disk of ESO 467-G051, an edge-on disk galaxy. The large projected distan…
1E 1207.4-5209, the peculiar Central Compact object in the G296.5+10.0 supernova remnant, has been proposed to be an "anti-magnetar" - a young neutron star born with a weak dipole field. Accretion, possibly of supernova fallback material, has also been invoked to explain a large surface temperature anisotropy as well as the generation of peculiar cyclotron absorption features superimposed to its thermal spectrum. Interestingly enough, a faint optical/infrared source was proposed as a possible counterpart to 1E 1207.4-5209, but later questioned, based on coarse positional coincidence. Consideri…
We present three epochs of early-time ultraviolet (UV) and optical HST/STIS spectroscopy of the young, nearby Type IIP supernova (SN) 2021yja. We complement the HST data with two earlier epochs of Swift UVOT spectroscopy. The HST and Swift UVOT spectra are consistent with those of other well-studied Type IIP supernovae (SNe). The UV spectra exhibit rapid cooling at early times, while less dramatic changes are seen in the optical. We also present Lick/KAIT optical photometry up to the late-time-tail phase, showing a very long plateau and shallow decline compared with other SNe IIP. Our modeling…
SN2017egm is the closest (z=0.03) H-poor superluminous supernova (SLSN-I) detected to date, and a rare example of an SLSN-I in a massive and metal-rich galaxy. Here we present the HST UV & optical spectra covering (1000 - 5500)A taken at +3 day relative to the peak. Our data reveal two sets of absorption systems, separated by 235 km/s, at redshifts matching the host galaxy, NGC3191 and its companion galaxy 73 arcsec apart. Weakly damped Lyman-alpha absorption lines are detected at these two redshifts, with HI column densities of $(3.0\pm0.8)\times10^{19}$ and $(3.7\pm0.9)\times10^{19}$\,cm$^{-…
It has been well established from a variety of observations that red supergiants (RSGs) loose a lot of mass in stellar wind. Dust formed in this emitted gas over a few decades before core-collapse can lead to substantial extinction and obscure the intrinsic luminosity of the progenitor RSG. This may lead to a difficulty in determining the range of progenitor masses that lead to the different classes of supernovae. Even the nearby, well studied supernovae with pre-explosion observations, such as SN 2013ej may suffer from this uncertainty in the progenitor mass. We explore here two different mas…
Late-Time HST UV Detections Reveal Eruptive Mass Loss and Circumstellar Interaction in a Quarter of Stripped-Envelope Supernovae
California Institute of Technology（加州理工学院）；Stockholm University（斯德哥尔摩大学）；Columbia University（哥伦比亚大学）；National Central University（中央大学）；Weizmann Institute of Science（魏茨曼科学研究所）
LensWatch. II. Improved Photometry and Time-delay Constraints on the Strongly Lensed Type Ia Supernova 2022qmx ("SN Zwicky") with HST Template Observations
