Credits: NASA/CXC/SAO
NASA’s newest X-ray eyes are open and ready for discovery!
Having spent just over a month in space, the Imaging X-ray Polarimetry Explorer (IXPE) is working and already zeroing in on some of the hottest, most energetic objects in the universe.
A joint effort between NASA and the Italian Space Agency, IXPE is the first space observatory dedicated to studying the polarization of X-rays coming from objects like exploded stars and black holes. Polarization describes how the X-ray light is oriented as it travels through space.
“The start of IXPE’s science observations marks a new chapter for X-ray astronomy,” said Martin Weisskopf, the mission’s principal investigator at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “One thing is certain: we can expect the unexpected.”
IXPE launched Dec. 9 on a Falcon 9 rocket into orbit 370 miles (600 kilometers) above Earth’s equator. The observatory’s boom, which provides the distance needed to focus X-rays onto its detectors, was deployed successfully on Dec. 15. The IXPE team spent the next three weeks checking out the observatory’s maneuvering and pointing abilities and aligning the telescopes.
Over the course of these tests, the team pointed IXPE at two bright calibration targets: 1ES 1959+650, a black-hole-powered galaxy core with jets shooting into space; and SMC X-1, a spinning dead star, or pulsar. The brightness of these two sources made it easy for the IXPE team to see where X-rays are falling on IXPE’s polarization-sensitive detectors and make small adjustments to the telescopes’ alignment.
What’s Next for IXPE?
On Jan. 11, IXPE began observing its first official scientific target – Cassiopeia A, or Cas A – the remains of a massive star that blew itself apart in a supernova around 350 years ago in our own Milky Way galaxy. Supernovae are filled with magnetic energy and accelerate particles to near light-speed, making them laboratories for studying extreme physics in space.
IXPE will provide details about Cas A’s magnetic field structure that can’t be observed in other ways. By studying the X-ray polarization, scientists can work out the detailed structure of its magnetic field and the sites where these particles pick up speed.
IXPE’s observations of Cas A will last about three weeks.
“Measuring X-ray polarization is not easy,” said Weisskopf. “You have to collect a lot of light, and the unpolarized light acts like background noise. It can take a while to detect a polarized signal.”
More about the IXPE Mission
IXPE transmits scientific data several times a day to a ground station operated by the Italian Space Agency in Malindi, Kenya. The data flows from the Malindi station to IXPE’s Mission Operations Center at the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP) and then to IXPE’s Science Operations Center at NASA Marshall for processing and analysis. IXPE’s scientific data will be publicly available from the High Energy Astrophysics Science Research Center at the NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
The Marshall science operations team also coordinates with mission operations team at LASP to schedule science observations. The mission plans to observe more than 30 planned targets during its first year. The mission will study distant supermassive black holes with energetic particle jets that light up their host galaxies. IXPE will also probe the twisted space-time around stellar-mass black holes and measure their spin. Other planned targets include different types of neutron stars, such as pulsars and magnetars. The science team has also reserved about a month to observe other interesting objects that may appear in the sky or brighten unexpectedly.
IXPE is a collaboration between NASA and the Italian Space Agency with partners and science collaborators in 12 countries. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations.
Malindi on the Kenyan coast probably is no longer how I remember it from early 1970s, huh? Ah well, old adventure stories nobody really cares about apparently means I’m just an old fart who’ll never travel to outer space.
Gone fishing …
Watching old 1930s movies, I understand why butlers would bring a phone with a looooong cord to the library or study or wherever the important people are — room extensions were expensive and hard to get. I don’t expect them to get out their cell phone.
But watching movies from the 1930s all the way up to the 1980s, where people drive around looking for a pay phone to report in, somehow never seems right. I keep on thinking, “reach into your pocket, get your cell phone out” even while I know what they are doing and why.
Brains are weird.
And international calls using old telephone technology for more than a few seconds were prohibitively expensive.
The story mentions Cas A whose explosion, you would think, should have been visible from Earth. One explanation for why it wasn’t is that the visible wavelengths were absorbed by interstellar dust. If that were true, we wouldn’t be able to see any stars in that vicinity. So, the dust explanation is a little too pat for my taste.
Is the x-ray polarization satellite a worthwhile endeavor? Given what we don’t know or don’t understand, I would be very surprised if it didn’t produce some useful clues. Whether scientists are smart enough to understand those clues is another story.
I think the article is wrong in this claim ” Cassiopeia A, or Cas A – the remains of a massive star that blew itself apart in a supernova around 350 years ago in our own Milky Way galaxy.”
Cassiopeia A is indeed located in our Milky Way galaxy, but it is over 10,000 light years away from us. The image shown above (taken by the Chandra X-ray telescope BTW) shows the extent of the explosion after the remnants had expanded for 350 years, 10,000 years ago.
So why wasn’t this observed in the visible spectrum? Because it was too far away (>10,000 ly). But also because these supernovae are so energetic that most of the photons released are in the X-ray spectrum:
https://chandra.harvard.edu/photo/2017/casa_life/
“X-ray telescopes such as Chandra are important to study supernova remnants and the elements they produce because these events generate extremely high temperatures — millions of degrees — even thousands of years after the explosion. This means that many supernova remnants, including Cas A, glow most strongly at X-ray wavelengths that are undetectable with other types of telescopes.“
Yes, it’s absorbed by the dust, which is denser in that region. Yes, you can see stars in that direction, but not in the vicinity of Cas A; the stars you see are between us and most of the dust. In fact most of the stars visible to us are nearby. IIRC, only a very large telescope can resolve stars at galactic distances or even at the distance of Cas A, and then only bright stars.
I think a mention of x-ray optics is warranted here.
https://en.wikipedia.org/wiki/X-ray_optics
“X-ray optics is the branch of optics that manipulates X-rays instead of visible light. It deals with focusing and other ways of manipulating the X-ray beams for research techniques such as X-ray crystallography, X-ray fluorescence, small-angle X-ray scattering, X-ray microscopy, X-ray phase-contrast imaging, X-ray astronomy etc.
Since X-rays and visible light are both electromagnetic waves they propagate in space in the same way, but because of the much higher frequency and photon energy of X-rays they interact with matter very differently. Visible light is easily redirected using lenses and mirrors, but because the real part of the complex refractive index of all materials is very close to 1 for X-rays,[1] they instead tend to initially penetrate and eventually get absorbed in most materials without changing direction much.”
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This telescope will be seeing things no other telescope has ever seen. I’m looking forward to its discoveries.
I always get a little peeved when a scientist uses imprecise language. Referring to light as unpolarized is just plain wrong. All light is polarized. The correct term would be randomly polarized and you are trying to determine the degree of polarization and direction of polarization that isn’t random. That is what Stokes Vectors are for.
The photo is obviously a false color image and should be so labelled.
But the point is to wow the masses with pretty pictures so they will fund esoteric endeavors that will produce no meaningful benefit to those paying the bill.
Right, we should put the money into much more worthwhile things, like chewing gum, cosmetics and guns. To hell with science, says the guy using a computer or phone to express his worthless opinions over the internet…
We should put the money into whatever we, as individuals, want. The government should not be reaching into our pockets and making that choice. I myself would fund this to some small extent. Others would not. The choice should be ours, not our betters’.
Straw man argument.
Perhaps “philanthropists” like Bezos, Buffett, Dorsey, Gates, Soros, Zuckerberg, et al, instead of spending billions rigging elections, could fund this research? You know, the way the rich did in the 18th, 19th, and pre-WW 20th century.
The government funds all the social welfare programs & all the scientific research, rigging elections is the only thing left for “philanthropists” to do.
Thomas ==> You are right — but that is not my objection. I have had a serious, educated person display a “photograph from NASA” of the Milky Way galaxy. When I tried to explain that it was impossible for mankind to have taken a photograph of our own galaxy — 100s of years to get a camera that far out into space, another hundreds of years for the image to travel back — their answer was “but NASA said so!”.
I don’t mind that they do it as long as it is correctly labelled.
Strictly speaking, it’s still a photograph: from photo -“light” + graph – “something written.” Visible light and x-rays are both forms of electromagnetic radiation, which have been captured to form an image. It’s just not taken in visible light. Also, if it’s ‘obviously’ a false colour image, there’d be little point in labelling it as such!
Adrian ==> It is obvious to me — maybe obvious to you. How many people do you know who would remark on how beautiful it is? So ALL the color is false — as it it not an image of light in those colors. “False color” is the correct technical term for this type of image. It doesn’t cost the makers anything to properly label it.
https://en.wikipedia.org/wiki/False_color
More good news! Looking forward to results!