arXiv subjects

Janette Suherli

Publications and source records attributed to Janette Suherli.

4 recordsLinked to original sources

arXiv2026

Using CFHT's SITELLE to Probe the Long-Sought Supernova Remnant Shell in the Crab Nebula

We present deep, wide-field integral field spectroscopy of the Crab nebula obtained with the imaging Fourier transform spectrometer SITELLE at the Canada--France--Hawaii Telescope (CFHT), to search for the long-sought forward shock. Our observations target the coronal line [Fe XIV]$\lambda$5303, a tracer of shock-heated gas, over two $11^{\prime} \times 11^{\prime}$ fields that probe projected radii of $\sim$2.4--10~pc west of the pulsar, encompassing the range in which a supernova shell is expected. After data processing and a search over the full field of view, we found no statistically significant [Fe XIV] emission in the surveyed regions. We derive a conservative average surface-brightness upper limit of $\lesssim 3.79 \times 10^{-17}~\mathrm{erg}~\mathrm{cm}^{-2}~\mathrm{s}^{-1}~\mathrm{arcsec}^{-2}$ over three representative annuli. This represents the deepest large-area optical constraint on coronal iron emission beyond the visible nebula from the Crab's putative supernova remnant (SNR) shell. Our results are consistent with scenarios in which the forward shock is expanding into a very low-density medium, the shocked gas is weak or underionized, or the shell lies outside the observed region. This work demonstrates the power of wide-field optical integral field spectroscopy for constraining faint, large-scale structures in SNRs.

astro-ph.HE↗

arXiv2026

A MUSE View of the Optical Torus within the Supernova Remnant 1E 0102.2-7219

We present new MUSE Narrow Field Mode with Adaptive Optics observations of the optical torus surrounding a Central Compact Object (CCO) candidate within the oxygen-rich supernova remnant 1E 0102.2-7219 (E0102) located in the Small Magellanic Cloud. These data provide nearly an order-of-magnitude improvement in spatial resolution over previous MUSE Wide Field Mode observations. The improved spatial resolution resolved the previously identified torus into a cavity-like structure with a sharply defined inner edge and diffuse, outer filamentary substructure. The emission shows continuous velocity connectivity, broad intrinsic line widths, and co-spatial contributions from neutral and partially ionized species, including O I, Ne I, [O I], [O II], and [O III]. Spatially resolved line-ratio maps indicate that the emission arises from a multiphase, non-equilibrium medium rather than a single homogeneous component. Comparison with photoionization and shock models shows that no single-component model within the explored parameter space can simultaneously reproduce both the strong neutral and high-ionization diagnostics, indicating that multiple physical conditions must coexist. We favor an interpretation in which shocks propagating through density inhomogeneities in the ejecta shape the observed morphology and excitation, while also considering alternative mechanisms linked to the central source, binary evolution, or interaction with an embedded object within the remnant.

astro-ph.HE↗

arXiv2025

Intertwined birth and death: a Herbig-Haro outflow resolves the distance to Vela Junior

The distance to the Vela Junior supernova remnant (RX J0852.0-4622 or G266.2-1.2) has long remained uncertain, limiting our understanding of its physical properties. Using VLT/MUSE integral field spectroscopy, we uncover chemical and kinematic connections between the nebula surrounding its Central Compact Object (CXOU J085201.4-461753) and the nearby Herbig-Haro outflow of Ve 7-27 (Wray 16-30), indicating a shared nitrogen-rich, Fe-peak-enhanced environment. This link ties stellar birth and death, with the young star Ve 7-27 embedded in material expelled by Vela Junior's massive progenitor, and the remnant's blast wave is expanding through the same medium. Adopting the Gaia-based distance to Ve 7-27, we revise Vela Junior's distance to $1.41\pm0.14$ kpc. At this distance, the remnant's physical radius is $23.3\pm2.3$ pc, and X-ray proper motions of the northwestern rim correspond to shock speeds of $(2.8\pm0.7)\times10^3$ to $(5.6\pm1.5)\times10^3$ km s$^{-1}$. These imply an age of $\sim$1.6-3.3 kyr and a very low ambient density, indicating that Vela Junior is expanding within a highly rarefied wind-blown cavity carved by a massive progenitor -- consistent with the non-detection of strong thermal X-ray emission. This distance update also resolves long-standing inconsistencies, with major implications for its energy budget, particle acceleration efficiency, and compact object evolution.

astro-ph.HE↗

arXiv2023

MUSE observations of the optical nebula surrounding the central compact object in the Vela Junior Supernova Remnant

Central Compact Objects (CCOs), neutron stars found near the centre of some Supernova Remnants (SNRs), have been almost exclusively studied in X-rays and are thought to lack the wind nebulae typically seen around young, rotation-powered pulsars. We present the first, spatially-resolved, morphological and spectroscopic study of the optical nebula observed at the location of CXOU J085201.4-461753, the CCO in the heart of the Vela Junior SNR. It is currently the only Galactic CCO with a spatially coincident nebula detected at optical wavelengths, whose exact nature remains uncertain. New MUSE integral field spectroscopy data confirm that the nebula, shaped like a smooth blob extending 8" in diameter, is dominated by [N II]$λλ$6548,6583 emission. The data reveals a distinct and previously unobserved morphology of the H$α$ emission, exhibiting an arc-like shape reminiscent of a bow shock nebula. We observe a significantly strong [N II] emission relative to H$α$, with the [N II]$λλ$6548,6583 up to 34 times the intensity of the H$α$ emission within the optical nebula environment. Notably, the [N II] and H$α$ structures are not spatially coincident, with the [N II] nebula concentrated to the south of the CCO and delimited by the H$α$ arc-like structure. We detect additional emission in [N I], He I, [S II], [Ar III], [Fe II], and [S III]. We discuss our findings in the light of a photoionization or Wolf-Rayet nebula, pointing to a very massive progenitor and further suggesting that very massive stars do not necessarily make black holes.

astro-ph.HE↗