Astronomers investigate a recently reactivated radio magnetar

March 14, 2019 by Tomasz Nowakowski, Phys.org report
Artist's conception of a powerful magnetar. Image credit: ESO/L. Calçada.

A UK-German team of astronomers has conducted observations of a peculiar radio magnetar known as XTE J1810–197, which turned on in December 2018 after an almost decade-long period of quiescence. Results of these observations provide more information about the magnetar properties, and were presented in a paper published March 6 on arXiv.org.

Magnetars are with extremely , more than quadrillion times stronger than magnetic field of our planet. Decay of magnetic fields in magnetars powers the emission of high-energy , for instance, in the form of X-rays or .

To date, only 23 magnetars have been identified and XTE J1810–197, with a spin period of around 5.54 seconds and magnetic field strength at a level of 2 trillion G, was detected as the first of only four known such objects to emit radio pulsations. Radio emission from XTE J1810–197 was discovered in 2004, one year after an X-ray outburst from this source was observed. The star subsequently exhibited highly variable pulsed radio emission until late 2008, when it entered a radio-quiet state.

Anticipating radio reactivation of XTE J1810–197, a group of astronomers led by Lina Levin of Jodrell Bank Centre for Astrophysics at the University of Manchester, UK, began observing this magnetar in 2009 with the Lovell telescope at Jodrell Bank Observatory (JBO). On December 8, 2018, the scientists detected a bright pulsed radio signal at 1.52 GHz from this source, which marked the end of a nearly decade of its radio-quietness.

"After spending almost a decade in a radio-quiet state, the Anomalous X-ray Pulsar XTE J1810–197 turned back on in early December 2018. We have observed this radio magnetar at 1.5 GHz with ∼daily cadence since the first detection of radio reactivation on December 8, 2018," the astronomers wrote in the paper.

According to the study, the pulse profile of XTE J1810–197 has changed significantly since detection. However, the profile changes observed during the first two months since the reactivation were less extreme when compared to what was observed the last time when this source was active.

"The pulse variations seen so far from the source have been significantly less dramatic, on timescales from hours to months, than seen in 2006," the paper reads.

The researchers report that the magnitude of the spin frequency derivative of XTE J1810–197 has increased by a factor of 2.6 over the 48-day data set, with the most rapid increase occurring during the first 15 days.

Moreover, the astronomers identified 50-millisecond oscillations seen in the pulse profile of the magnetar for about 10 days after it was re-detected. These oscillations have a characteristic frequency of 20 Hz and are seen at different frequencies and different telescopes at the same time. The authors of the paper assume that such oscillations could be related to triggered in the neutron star crust with a wide spectrum of frequencies.

In concluding remarks, the researchers propose further monitoring of XTE J1810–197 in order to find out whether or not the pulse profile of the will experience more variations over time.

Explore further: Astronomers find unexpected 'heartbeats' in star

More information: L Levin et al. Spin frequency evolution and pulse profile variations of the recently re-activated radio magnetar XTE J1810-197. arXiv:1903.02660 [astro-ph.HE]. arxiv.org/abs/1903.02660

Related Stories

Astronomers find unexpected 'heartbeats' in star

August 23, 2006

Astronomers using CSIRO's Parkes telescope in eastern Australia have detected radio "heartbeats" from a star that was not expected to have them. A US-Australian research team found that a "magnetar" -- a kind of star with ...

Slowest-spinning radio pulsar detected by astronomers

September 17, 2018

An international team of astronomers has discovered a new radio pulsar as part of the LOFAR Tied-Array All-Sky Survey (LOTAAS). The newly detected object, designated PSR J0250+5854, turns out to be the slowest-spinning radio ...

Two sides of the same star

May 30, 2018

If you've ever heard of the phrase two sides of the same coin, you know it means two things that at first appear to be unrelated are actually parts of the same thing. Now, a fundamental example can be found in the deep recesses ...

Magnetar mysteries in our galaxy and beyond

January 10, 2019

In a new Caltech-led study, researchers from campus and the Jet Propulsion Laboratory (JPL) have analyzed pulses of radio waves coming from a magnetar—a rotating, dense, dead star with a strong magnetic field—that is ...

A magnetar just woke up after three years of silence

April 10, 2018

When stars reach the end of their main sequence, they undergo a gravitational collapse, ejecting their outermost layers in a supernova explosion. What remains afterward is a dense, spinning core primarily made up of neutrons ...

Recommended for you

A decade on, smartphone-like software finally heads to space

March 20, 2019

Once a traditional satellite is launched into space, its physical hardware and computer software stay mostly immutable for the rest of its existence as it orbits the Earth, even as the technology it serves on the ground continues ...

Tiny 'water bears' can teach us about survival

March 20, 2019

Earth's ultimate survivors can weather extreme heat, cold, radiation and even the vacuum of space. Now the U.S. military hopes these tiny critters called tardigrades can teach us about true toughness.

Researchers find hidden proteins in bacteria

March 20, 2019

Scientists at the University of Illinois at Chicago have developed a way to identify the beginning of every gene—known as a translation start site or a start codon—in bacterial cell DNA with a single experiment and, through ...

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Nik_2213
not rated yet Mar 14, 2019
Is this definitely a 'singleton' star, or could there be a companion on a decade-long orbit ??
rrwillsj
3 / 5 (1) Mar 16, 2019
well, it will be most tedious when the looneyticks pile out of their clown car, yo denounce the data collected & the conclusions derived from scientific research.

Demanding that everyone play braindead. That it is impossible that the stellar mass contracted into a Neutron Star & then began producing super-duoer magnetic fields. No matter the Empirical Ebidence produced by accredited researchers,

The woomongers will insist that their drunken deities first plasmaspazzic aethernuttiness electrouniversilly sparkles magically produced the Neutron Star without any help from that nasty Big Bully Gravity.

Which they will endlessly insist is created after the pretty lights. When their drunken deities beat their thundermugs on the tabletop in appreciation of the mesmerizing sight of the galvanic light show.
Nik_2213
not rated yet Mar 17, 2019
Sorry, @RRW, I know PhysOrg comments suffer from witless woosters and flagrant nuttiness, but mine was a serious question regarding one recognised route for periodic mass transfer...
rrwillsj
5 / 5 (1) Mar 17, 2019
Nik, ol'buddy. I regret that you misunderstood my intent.
I will not pretend I am competent to answer your question.

Which I consider a comment in good faith.
I look forward ti the answers from the few Real Scientists who frequent Phys.org.
Who have shown they are competent to answer you.

Even if I fail to understand their explanation? I enjoy the challenge of trying!

You probably find me a gadfly, adisruptive influence.
Perhaps you should follow your compatriots who have set me to "ignore"?
I promise I do not take offense at such a designation.
Actually, thinking about it?
I find it amusing. Yes, I do have a perverse sense of humor..

Frankly & Ernestly, if there is any basic intent on my part?
I am devoted to my patron goddess, Trickster Coyote.
She inspires my intense anger to the struggle against the flood of online frauds & fakirs, denialists & antivaxxers. As criminally traitorous bots & malicious agents of anti-science, anti-human propaganda.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.