相关论文: The distribution of radioactive $^{44}$Ti in Cassi…

Cassiopeia A, one of the most intriguing galactic supernova remnants, has been a target of many observational efforts including most recent observations by ALMA, Hubble, Herschel, Spitzer, NuSTAR, Integral, and other observatories. We use…

We present a long-exposure (~10 hr) image of the supernova (SN) remnant Cassiopeia A (Cas A) obtained with the UKIRT 3.8-m telescope using a narrow band filter centered at 1.644 um emission. The passband contains [Fe II] 1.644 um and [Si I]…

Two long observations of Cas A supernova remnant were made by the \emph{Rossi X-ray Timing Explorer} in 1996 and 1997 to search for hard X-ray line emission at 67.9 and 78.4 keV from decay of $^{44}$Ti formed during the supernova event.…

Further analysis of X-ray spectroscopy results recently obtained from the MOS CCD cameras on-board XMM-Newton provides a detailed description of the hot and cool X-ray emitting plasma in Cas A. Measurement of the Doppler broadening of the…

The supernova remnant Cassiopeia A (Cas A) is one of the few remnants in which it is possible to observe unshocked ejecta. A deep 1.64 micron image of Cas A shows a patch of diffuse emission from unshocked ejecta, as well as brighter…

We present new reddening measurements towards the young supernova remnant Cassiopeia A, using two techniques not previously applied to this object. Our observations of the near-infrared [Fe II] 1.257 micron and 1.644 micron lines show the…

The large abundance ratio of $^{44}Ti/^{56}Ni$ in Cas A is puzzling. In fact, the ratio seems to be larger than the theoretical constraint derived by Woosley & Hoffman (1991). However, this constraint is obtained on the assumption that the…

We present new evidence that the bright non-thermal X-ray emission features in the interior of the Cassiopeia A supernova remnant (SNR) are caused by inward moving shocks based on Chandra and NuSTAR observations. Several bright…

We analyze and model the infrared spectrum of the Cassiopeia A supernova remnant, with the aim of determining the masses of various elements in the unshocked ejecta. In this way we complement the survey of the X-ray emitting ejecta of Hwang…

We present results from the first light observations of the Cassiopeia A (Cas A) supernova remnant (SNR) by the Chandra X-ray Observatory. The X-ray spectrum varies on all spatial scales down to the instrumental limit (0.02 pc at the SNR).…

Core-collapse supernovae (CCSNe) produce large ($\gtrsim 0.1 \, {\rm M}_\odot$) masses of dust, and are potentially the primary source of dust in the Universe, but much of this dust may be destroyed before reaching the interstellar medium.…

Context. Deriving the mass and large-scale asymmetries of radioactive isotopes offers valuable insights into the complex phases of a supernova explosion. Important examples are $^{56}$Ni, with its decay products $^{56}$Co and $^{56}$Fe, and…

Radioactive isotopes such as 44Ti offer probably the most direct probe into nucleosynthesis environments in the interior of exploding stars, when the associated gamma-ray activities in the explosion remnant are detected and translated back…

We present Hubble Space Telescope WFC3/IR images of the Cassiopeia A supernova remnant that survey its high-velocity, S-rich debris in the NE jet and SW counterjet regions through [S III] 9069, 9531 and [S II] 10,287 - 10,370 line…

Using data from the Chandra X-Ray Observatory, we revisited the reverse shock in the supernova remnant (SNR) Cassiopeia A.Based on the spectroscopic of a series of annuli in the northwest (NW) and southeast (SE), we get the radial profiles…

The effects of plasma elemental composition and ionization state on the effective decay rate of 44Ti are investigated. We essentially follow the methods of the first authors to treat this topic, Mochizuki et al., but use more realistic…

The merger between the carbon (C) and oxygen (O) shells hours to days before the collapse of a massive star significantly changes its nucleosynthesis, which is reflected in the elemental ratios observed in supernova remnants (SNRs). We…

We present Chandra ACIS X-ray observations of the Galactic supernova remnant Cassiopeia A taken in December 2007. Combining these data with previous archival Chandra observations taken in 2000, 2002, and 2004, we estimate the remnant's…

We present initial results from a JWST survey of the youngest Galactic core-collapse supernova remnant Cassiopeia A (Cas A), made up of NIRCam and MIRI imaging mosaics that map emission from the main shell, interior, and surrounding…

Core collapse supernovae are thought to be one of the main sources in the galaxy of elements heavier than iron. Understanding the origin of the elements is thus tightly linked to our understanding of the explosion mechanism of supernovae…