Astronomers discover a large cavity around the Tycho's supernova

Astronomers discover a large cavity around the Tycho's supernova
The large-field WISE [12–4.6] µm infrared image around the Tycho’s supernova remnant (SNR). The red circle shows the position and size of the shell-like structure in the Tycho’s SNR, while the yellow dashed ellipse shows the cavity found in the MWISP CO images. The three white dashed lines are shown to guide the eye for the stream-like structures seen in the CO images. The white arrows mark the positions of the pillar-like structures found in the WISE image. Credit: Chen et al., 2016.

Chinese astronomers have detected a large cavity existing around Tycho's supernova, also know as SN 1572, exhibiting stream-like structures. The findings, reported in a paper published Aug. 18 on arXiv.org, show that the environments of the supernovae may be much more complicated than previously thought.

SN 1572 lies between 8,000 to 10,000 light years from the Earth in the constellation Cassiopeia. It is a well-established type Ia , one of about eight supernovae visible to the naked eye in historical records. As one of the most popular supernova remnants in our galaxy, it has been widely observed in the entire electromagnetic spectrum, and astronomers have discovered a shell-like structure produced by the shocks from the explosion as well as circumstellar material and dust.

More recent observations of Tycho's supernova were conducted by a team of Chinese astronomers led by Xuepeng Chen of the Purple Mountain Observatory (PMO) in Nanjing, China. They used the 13.7-meter millimeter-wavelength telescope of the Qinghai station of PMO at Delingha in China to perform large-field and high-sensitivity carbon monoxide (CO) molecular line observations of SN 1572. The scientists observed the supernova from November 2011 to February 2016 as part of the Milky Way Imaging Scroll Painting (MWISP) survey, which investigates the nature of the molecular gas along the northern Galactic Plane.

"We present large-field CO (1-0) molecular line observations toward the Tycho's supernova remnant, using the PMO 13.7-meter telescope. Based on the CO observations, we find a large with radii of 0.3 degrees by 0.6 degrees around the remnant, which is further confirmed by the complementary infrared images from the space telescopes," the researchers wrote in the paper.

The team estimated that the cavity is located about 8,000 light years away and has radii of 42 and 88 light years. Their calculations allowed them to estimate that this cavity is expanding at a velocity of approximately 4 km s-1.

Moreover, the astronomers distinguished stream-like structures in the cavity that could be part of a larger cavity seen along the line of sight. They noted that these structures may also record the accretion winds from the progenitor system. Due to these uncertainties, the team calls for further observations that could illuminate the real nature of these structures.

"In the wind-regulated accretion models, the accretion wind could last for few million years, and the white dwarf may explode as a type Ia supernova while the accretion wind is still active. Therefore, another possible explanation is that these stream-like structures actually record the accretion winds from the progenitor system. This scenario is somehow supported by the infrared observations, in which knot-like structures are also found in the southwest and west of the cavity," the paper reads.

The scientists also investigated the origin of the cavity. They excluded the possibility that it could be produced by bright star in the region or the option that it was randomly distributed. According to the paper, the most plausible hypothesis taken into account is that it could be explained by the accretion wind from the progenitor system of the Tycho's supernova.

"The discovery of the Tycho's cavity also gives us an alert that the environments of the supernovae Ia may be much more complicated than we thought before," the researchers concluded.


Explore further

Collaboration uncovers the origin of extraordinary supernovae

More information: Discovery of A Large Cavity around the Tycho's Supernova Remnant, arXiv:1608.05329 [astro-ph.GA] arxiv.org/abs/1608.05329

Abstract
We present large-field (3x2 deg^2) and high-sensitivity CO(1-0) molecular line observations toward the Tycho's supernova remnant, using the 13.7-meter radio telescope of the Purple Mountain Observatory. Based on the CO observations, we discover a large cavity around the remnant, with radii of about 0.3x0.6 deg (or ~13x27 pc at a distance of 2.5 kpc), which is further supported by the complementary infrared images from the space telescopes. The observed CO line broadenings and asymmetries in the surrounding clouds, the infrared pillar-like structures found around the remnant, in concert with enhanced 12CO(2-1)/(1-0) intensity ratio detected in previous studies, indicate strong interaction of the large cavity with a wind in the region. After excluding the scenario of a large bubble produced by bright massive stars, we consider that the large cavity could be most likely explained by the accretion wind from the progenitor system of the Tycho's supernova. The CO gas kinematics indicates that the large cavity is expanding at a velocity of about 4 km/s. The estimated velocity (~1000 km/s, with a mass-loss rate of ~10^(-6)*M_sun*yr^(-1)) and timescale (~4x10^6 yr) of the wind needed for creating such a cavity are consistent with the predictions from the wind-regulated accretion model. We conclude that Tycho's supernova, the prototypical Type-Ia supernova in the Milky Way, arose from accretion onto a white dwarf.

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Citation: Astronomers discover a large cavity around the Tycho's supernova (2016, August 23) retrieved 18 September 2019 from https://phys.org/news/2016-08-astronomers-large-cavity-tycho-supernova.html
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Aug 23, 2016
Fascinating, just wish we could find the answer about what "material" space and the universe is made of, and what lies on the other side, we seem to continually hit a brick wall when trying to find these answers, i'm tired of people telling me that the universe is all there is and that there is nothing on the other side,

Perhaps it is impossible to see what it looks like in the physical form on the other side, however there must be something that holds this universe in place and makes it work like it does, and there must be a way to understand how it works and what it would look like if we could try and describe it physically, is there some good documentaries about the multiverse ?

Aug 23, 2016
Think of it more this way Helo, The universe is, by definition, everything describable by science. There is no way there can be "more" of it, because it is definitively everything.

What is often confused however, is a secondary definition of the universe which is "The 3+1 dimensional brane of space-time in which we are embedded, and all the material/energy within it." Ie, all the space and all the time you could possibly travel to from here, including if you could move instantly and/or backwards in time.

Even more confusing is that there is an "observable" universe, which is the subvolume of the above definition that includes all the space-time for which light has had sufficient time to travel to us.

Aug 23, 2016
There could, as a thought experiment, be other space-time branes, other 'universes' (in the second sense of the word), but if no matter or energy from our universe can get to them, or from them to us, then they remain unobservable, and outside the proper realm of 'science.'

Another meaning often ascribed to 'multiverse' is Everett's many worlds interpretation of quantum mechanics. In a more contemporary read of this interpretation, you might say that quantum particles occupy real superpositions, and when they interact with other objects, they just entangle those other objects into superpositions as well. This includes measurement devices and our own memories. Thus when we 'measure' a particle, our state becomes a superposition correlated with the possible particle states, and we only 'remember' seeing one property or another, because we can't 'know' what our other superposed states saw. But this has nothing to do with your question. Just a caveat when you go looking.

Aug 24, 2016
Interesting thoughts Shavera, i like your continued answer which is in line with my fascination about there being more than what we can observe or physically see in this realm and what our realm's/human perception, physical laws limit us to observe and understand.
**conti**

Aug 24, 2016
The other night i was thinking, what if space is like water, you cannot dig through water as there would only be more water filling the water you dig away, however if from down below the ocean you swim upwards, eventually you will get out of the water, i feel that there must be something outside of space like there is something outside of water, but in this case we might not be able to exist physically outside of our universe

Your superposition explanation is very interesting too, for it to be so convincing and real would be beyond fascinating, that leaves me to wonder how all the different dimensions or multiverses works together and it's purpose, but this i guess is rabbit hole that can extend further than imagination.

Aug 24, 2016
I love how this conversation is relevant to the study in question (about the information possibly "recorded" in the debris surrounding a Type 1a supernova). The research is basically laying the foundation for further research, as in what might the chemical composition of this material suggest about the evolution of the event, and what might that suggest generally about the process as we understand it? Hence, it's incremental science, I would say. A hint at a possible answer to something highly specific with a vast array of possible questions which might lead to further studies.

As for the universe and its composition, one perspective is that time and space "exist" only insofar as we perceive them, in that they make sense to our neurosensory apparatus - eyes, nerves, brain, etc. All "points" in time and space are "real" in a quantum mechanical sense, but we "move through" those points on our way from one observation: I am a small child, to another: I'm dead. Just a thought. :)

Aug 24, 2016
Not sure why these pillar like structures within the cavity are such a mystery. It's almost as if these astrophysicists are unaware of elementary aspects of plasma processes.
https://www.googl..._AUICSgD


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