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Register a new userThe Distance and the near-IR extinction of the Monoceros Supernova Remnant
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Supernova remnants (SNRs) embody the information of the influence on dust properties by the supernova explosion. Based on the color indexes from the 2MASS photometric survey and the stellar parameters from the SDSS$-$DR12$/$APOGEE and LAMOST$-$DR2$/$LEGUE spectroscopic surveys, the near-infrared extinction law and the distance of the Monoceros SNR are derived together with its nearby two nebulas -- the Rosette Nebula and NGC 2264. The distance is found at the position of the sharp increase of interstellar extinction with distance and the nebular extinction is calculated by subtracting the foreground interstellar extinction. The distance of the Monoceros SNR is determined to be $1.98,$kpc, larger than previous values. Meanwhile, the distance of the Rosette Nebula is $1.55,$kpc, generally consistent with previous work. The distance between these two nebulas suggests no interaction between them. The distance of NGC 2264, $1.20,$kpc, exceeds previous values. The color excess ratio, $E_{rm JH}/E_{rm JK_S}$, is 0.657 for the Monoceros SNR, consistent with the average value 0.652 for the Milky Way (Xue et al. 2016). The consistency is resulted from that the SNR material is dominated by interstellar dust rather than the supernova ejecta. $E_{rm JH}/E_{rm JK_S}$ equals to 0.658 for the Rosette Nebula, further proving the universality of the near-infrared extinction law.
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We present a three dimensional (3D) extinction analysis in the region toward the supernova remnant (SNR) S147 (G180.0-1.7) using multi-band photometric data from the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC), 2MASS and WISE. We isolate a previously unrecognised dust structure likely to be associated with SNR S147. The structure, which we term as S147 dust cloud, is estimated to have a distance $d$ = 1.22 $pm$ 0.21 kpc, consistent with the conjecture that S147 is associated with pulsar PSR J0538 + 2817. The cloud includes several dense clumps of relatively high extinction that locate on the radio shell of S147 and coincide spatially with the CO and gamma-ray emission features. We conclude that the usage of CO measurements to trace the SNR associated MCs is unavoidably limited by the detection threshold, dust depletion, and the difficulty of distance estimates in the outer Galaxy. 3D dust extinction mapping may provide a better way to identify and study SNR-MC interactions.
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We determine the slope of the near infrared extinction power law (A$_{lambda} propto lambda^{-alpha}$) for 8 regions of the Galaxy between l$sim27^{circ}$ and $sim100^{circ}$. UKIDSS Galactic Plane Survey data are compared, in colour-colour space, with Galactic population synthesis model data reddened using a series of power laws and convolved through the UKIDSS filter profiles. Monte Carlo simulations allow us to determine the best fit value of $alpha$ and evaluate the uncertainty. All values are consistent with each other giving an average extinction power law of $alpha$=2.14$^{+0.04}_{-0.05}$. This is much steeper than most laws previously derived in the literature from colour excess ratios, which are typically between 1.6 and 1.8. We show that this discrepancy is due to an inappropriate choice of filter wavelength in conversion from colour excess ratios to $alpha$ and that effective rather than isophotal wavelengths are more appropriate. In addition, curved reddening tracks, which depend on spectral type and filter system, should be used instead of straight vectors.
Based on the accurate color excess $E_{rm G_{BP},G_{RP}}$ of more than 4 million stars and $E_{rm NUV,G_{BP}}$ of more than 1 million stars from citet{2021ApJS..254...38S}, the distance and the extinction of the molecular clouds in the MBM catalog at $|b|>20^{circ}$ are studied in combination with the distance measurement of emph{Gaia}/EDR3. The distance as well as the color excess is determined for 66 molecular clouds. The color excess ratio $E_{rm G_{BP},G_{RP}}/E_{rm NUV,G_{BP}}$ is derived for 39 of them, which is obviously larger and implies more small particles at smaller extinction. In addition, the scale height of the dust disk is found to be about 100 pc and becomes large at the anticenter direction due to the disk flaring.
We present an analysis of the gamma-ray measurements by the Large Area Telescope onboard the textit{Fermi Gamma-ray Space Telescope} in the region of the supernova remnant~(SNR) Monoceros Loop~(G205.5$+$0.5). The brightest gamma-ray peak is spatially correlated with the Rosette Nebula, which is a molecular cloud complex adjacent to the southeast edge of the SNR. After subtraction of this emission by spatial modeling, the gamma-ray emission from the SNR emerges, which is extended and fit by a Gaussian spatial template. The gamma-ray spectra are significantly better reproduced by a curved shape than a simple power law. The luminosities between 0.2--300~GeV are $sim$~$4 times 10^{34}$~erg~s$^{-1}$ for the SNR and $sim$~$3 times 10^{34}$~erg~s$^{-1}$ for the Rosette Nebula, respectively. We argue that the gamma rays likely originate from the interactions of particles accelerated in the SNR. The decay of neutral pions produced in nucleon-nucleon interactions of accelerated hadrons with interstellar gas provides a reasonable explanation for the gamma-ray emission of both the Rosette Nebula and the Monoceros SNR.
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