اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدConstraints on supernova progenitors from spatial correlations with H-alpha emission
28
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We have attempted to constrain the progenitors of all supernova types, through correlations of the positions of historical supernovae with recent star formation, as traced by H-alpha emission. Through pixel statistics we have found that a large fraction of the SNII population do not show any association with current star formation, which we put down to a runaway fraction of these progenitors. The SNIb/c population accurately traces the H-alpha emission, with some suggestion that the SNIc progenitors show a higher degree of correlation than the SNIb, suggesting higher mass progenitors for the former. Overall the SNIa population only show a weak correlation to the positions of HII regions, but as many as a half may be associated with a young stellar population.
قيم البحث
اقرأ أيضاً
We present observational constraints on the nature of the different core-collapse supernova types through an investigation of the association of their explosion sites with recent star formation, as traced by H-alpha +[NII] line emission. We discuss r
esults on the analysed data of the positions of 168 core-collapse supernovae with respect to the H-alpha emission within their host galaxies. From our analysis we find that overall the type II progenitor population does not trace the underlying star formation. Our results are consistent with a significant fraction of SNII arising from progenitor stars of less than 10 solar masses. We find that the supernovae of type Ib show a higher degree of association with HII regions than those of type II (without accurately tracing the emission), while the type Ic population accurately traces the H-alpha emission. This implies that the main core-collapse supernova types form a sequence of increasing progenitor mass, from the type II, to Ib and finally Ic. We find that the type IIn sub-class display a similar degree of association with the line emission to the overall SNII population, implying that at least the majority of these SNe do not arise from the most massive stars. We also find that the small number of SN `impostors within our sample do not trace the star formation of their host galaxies, a result that would not be expected if these events arise from massive Luminous Blue Variable star progenitors.
We present new {it Hubble Space Telescope} images of high-velocity H-$alpha$ and Lyman-$alpha$ emission in the outer debris of SN~1987A. The H-$alpha$ images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time
we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H$alpha$ imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals ($-$7,500~$<$~$V_{obs}$~$<$~$-$2,800 km s$^{-1}$) and (1,000~$<$~$V_{obs}$~$<$~7,500 km s$^{-1}$), $dot{M_{H}}$ = 1.2~$times$~10$^{-3}$ M$_{odot}$ yr$^{-1}$. We also present the first Lyman-$alpha$ imaging of the whole remnant and new $Chandra$ X-ray observations. Comparing the spatial distribution of the Lyman-$alpha$ and X-ray emission, we observe that the majority of the high-velocity Lyman-$alpha$ emission originates interior to the equatorial ring. The observed Lyman-$alpha$/H-$alpha$ photon ratio, $langle$$R(Lalpha / Halpha)$$rangle$ $approx$~17, is significantly higher than the theoretically predicted ratio of $approx$ 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-$alpha$ emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-$alpha$ and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-$alpha$ production mechanism in SN 1987A at this phase in its evolution.
Observationally, supernovae (SNe) are divided into subclasses pertaining to their distinct characteristics. This diversity reflects the diversity in the progenitor stars. It is not entirely clear how different evolutionary paths leading massive stars
to become a SN are governed by fundamental parameters such as progenitor initial mass and metallicity. This paper places constraints on progenitor initial mass and metallicity in distinct core-collapse SN subclasses, through a study of the parent stellar populations at the explosion sites. Integral field spectroscopy (IFS) of 83 nearby SN explosion sites with a median distance of 18 Mpc has been collected and analysed, enabling detection and spectral extraction of the parent stellar population of SN progenitors. From the parent stellar population spectrum, the initial mass and metallicity of the coeval progenitor are derived by means of comparison to simple stellar population models and strong-line methods. Additionally, near-infrared IFS was employed to characterise the star formation history at the explosion sites. No significant metallicity differences are observed among distinct SN types. The typical progenitor mass is found to be highest for SN Ic, followed by type Ib, then types IIb and II. SN IIn is the least associated with young stellar populations and thus massive progenitors. However, statistically significant differences in progenitor initial mass are observed only when comparing SNe IIn with other subclasses. Stripped-envelope SN progenitors with initial mass estimate lower than 25~$M_odot$ are found; these are thought to be the result of binary progenitors. Confirming previous studies, these results support the notion that core-collapse SN progenitors cannot arise from single-star channel only, and both single and binary channels are at play in the production of core-collapse SNe. [ABRIDGED]
In this paper we present the most up-to-date list of nearby galaxies with optically detected supernova remnants (SNRs). We discuss the contribution of the H{alpha} flux from the SNRs to the total H{alpha} flux and its influence on derived star format
ion rate (SFR) for 18 galaxies in our sample. We found that the contribution of SNRs flux to the total H{alpha} flux is 5 $pm$ 5 per cent. Due to the observational selection effects, the SNRs contamination of SFRs derived herein represents only a lower limit.
Using a sample of dwarf irregular galaxies selected from the ALFALFA blind HI-survey and observed using the VIMOS IFU, we investigate the relationship between H$alpha$ emission and Balmer optical depth ($tau_{text{b}}$). We find a positive correlatio
n between H$alpha$ luminosity surface density and Balmer optical depth in 8 of 11 at $geq$ 0.8$sigma$ significance (6 of 11 at $geq$ 1.0$sigma$) galaxies. Our spaxels have physical scales ranging from 30 to 80 pc, demonstrating that the correlation between these two variables continues to hold down to spatial scales as low as 30 pc. Using the Spearmans rank correlation coefficient to test for correlation between $Sigma_{text{H}alpha}$ and $tau_{text{b}}$ in all the galaxies combined, we find $rho = 0.39$, indicating a positive correlation at 4$sigma$ significance. Our low stellar-mass galaxy results are in agreement with observations of emission line regions in larger spiral galaxies, indicating that this relationship is independent of the size of the galaxy hosting the emission line region. The positive correlation between H$alpha$ luminosity and Balmer optical depth within spaxels is consistent with the hypothesis that young star-forming regions are surrounded by dusty birth-clouds.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
