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Xray burst spotted in the galactic bulge

first_img Explore further (Phys.org)—Using the JEM-X telescope onboard the INTEGRAL space observatory, astronomers have discovered a new X-ray burst in the galactic bulge. The X-ray burst was detected from the faint unidentified transient source know as IGR J17445-2747. The discovery is reported in a paper published Sept. 8 on arXiv.org. First detected in 2003 by the IBIS/ISGRI gamma-ray telescope, IGR J17445-2747 was initially classified as a faint, unidentified persistent source. Subsequent observations of this source were conducted with the aim of detecting any outbursts that could be helpful in determining its nature. However, no such outbursts were discovered to date.This situation changed in April 2017 when a team of Russian astronomers from the Space Research Institute in Moscow spotted a type I X-ray burst from IGR J17445-2747. The group, led by Ilya Mereminskiy, discovered the burst by analyzing the data obtained during scanning observations of the galactic center region with the Joint European X-ray Monitor (JEM-X) telescope onboard ESA’s INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) space mission. “We reported the detection of a type I X-ray burst from the poorly studied transient X-ray source IGR J17445-2747 in the galactic bulge,” the researchers wrote in the paper.X-ray bursts are among the most energetic events observed in the universe. They are believed to be thermonuclear explosions occurring near the surface of accreting neutron stars. Such events occur in low-mass X-ray binary systems where a neutron star and low-mass main sequence star are in orbit around one another.Astronomers divide X-ray bursts into two categories: type I and type II. Type I bursts have a sharp rise followed by a slow and gradual decline of the luminosity profile, while type II bursts are characterized by a quick pulse shape, and may have many fast bursts separated by minutes. First X-ray burst was discovered in 1975 and so far, almost all of the detected X-ray bursts were found to be of type I.New observations from the JEM-X instrument show that IGR J17445-2747 is another source exhibiting type I X-ray bursts. The newly detected burst has a shape typical for type I bursts, including a fast rise shorter than five seconds and a much slower decay lasting about 15 seconds. The findings indicate that IGR J17445-2747 is an accreting neutron star with a weak magnetic field in a low-mass X-ray binary.”Such bursts are a sign of a thermonuclear explosion of accreted matter on the surface of a neutron star with a weak magnetic field in a low-mass X-ray binary. This is also confirmed by the almost blackbody spectrum detected during the burst,” the paper reads.Furthermore, few days after the discovery of the burst from IGR J17445-2747, the source was observed with the X-Ray Telescope (XRT) onboard NASA’s Swift Gamma-Ray Burst Mission in order to estimate its accurate position. These observations allowed the researchers to determine that IGR J17445-2747 is most likely located in the galactic bulge, between 16,300 and 40,000 light years away from the Earth. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. © 2017 Phys.org JEM-X sky images (S/N maps) in the 3–20 keV band obtained on April 10, 2017: (a) over the entire observation during which the burst was detected; (b) within 13 s near the burst maximum. The detected bright persistent sources are indicated in the left image. The white circle marks IGR J17445-2747. Credit: Mereminskiy et al., 2017. New accreting millisecond X-ray pulsar discovered More information: IGR J17445-2747 – yet another X-ray burster in the Galactic bulge, arXiv:1709.02775 [astro-ph.HE] arxiv.org/abs/1709.02775AbstractThe discovery of a type I X-ray burst from the faint unidentified transient source IGR J17445-2747 in the Galactic bulge by the JEM-X telescope onboard the INTEGRAL observatory is reported. Type I bursts are believed to be associated with thermonuclear explosions of accreted matter on the surface of a neutron star with a weak magnetic field in a low-mass X-ray binary. Thus, this observation allows the nature of this source to be established. Citation: X-ray burst spotted in the galactic bulge (2017, September 18) retrieved 18 August 2019 from https://phys.org/news/2017-09-x-ray-galactic-bulge.htmllast_img read more

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8 Take a boat out onto Plitvice Lakes Croatias m

first_img8. Take a boat out onto Plitvice LakesCroatia’s most popular national park is home to the sixteen electric blue Plitvice lakes. They are interconnected by impressive waterfalls and surrounded by dense forest. You can walk or take a panoramic shuttle bus around the park or take a boat onto Lake Kozjak and row across its tranquil waters. Over the past decade Croatia has emerged as one of the most exciting countries to visit in Europe. It has become one of the most sought after destinations for sun worshippers with its Dalmatian coastline boasting miles of pristine white beaches.However, that is not to say it’s only good for beach bums. For history buffs there are a plethora of monuments from the Roman, Byzantine, Venetian and Austro-Hungarian eras along with seven UNESCO world heritage sites. The countryside offers miles of unspoiled landscape, rugged mountains and beautiful national parks and its capital – Zagreb – still remains unspoiled by the tourist masses. We reveal the top 10 things not to be missed in Croatia!1. Party in a palace in SplitIf you visit Croatia’s second city, chances are you’ll spend the majority of your time in Diocletian’s Palace. Originally built by the Roman emperor Diocletian at the turn of the fourth century, it is now the heart and soul of modern Split. Within the walls of this imposing fortress you’ll find most of the city’s bars, restaurants and shops. You can easily get lost in this labyrinth of winding narrow streets, but chances are you’ll find a group of pub crawlers along the way that’ll help you find your way – to the next bar.Find flights to Split Related5 best beach destinations for familiesSun, sea, sand and plenty of activities to keep the kids (and the adults!) entertained. We reveal the top 5 beach destinations for families.Top 15 attractions and things to do in SplitFancy a weekend away, lazing in cool curbside cafés, exploring Roman ruins and island-hopping around the Adriatic? Check out Split, Croatia, with our top tips on what to see and do.15 Mediterranean holiday destinations you can’t miss this summerCruising for a deal on Mediterranean holidays this summer? Who can blame you. Check out these beautiful beaches, small islands and the best places to visit in the Mediterranean Sea, from Spain to Croatia. We’ll see you there for an Aperol spritz. 2. Take a walking tour of ZagrebDespite often being overshadowed by the perhaps slightly livelier Eastern European cities, Croatia’s capital should not be missed! Best seen on foot, it is an easy city to stroll around and admire its Austro-Hungarian architecture, scenic parks and busy squares. Do not miss Crkva Svetog Marka, a dainty little church that’s tiled roof features the Croation coat of arms.Find flights to Zagreb Read more: 11 incredible secret European islands7. Have an unusual cinematic experience in PulaAmongst the various Roman sites throughout the city, Pula’s well preserved amphitheatre remains the most impressive. Slap bang in the city centre, it is the hub for most of Pula’s cultural events, from cinema screenings to concerts and festivals.Find flights to Pula 3. Mend a broken heartIt is understandable, that unless you are a budding art enthusiast or culture vulture, galleries and museums can start to become one and the same. Although Zagreb has plenty of stunning galleries and museums catering to a variety of interests, it is the Museum of Broken Relationships that stands out as a must visit. The museum’s aim is to help people overcome the collapse of a relationship by contributing to the Museum’s collection. Here you’ll find various items (toys, clothing… an axe!) along with the stories of their significance to people from all over the world. It is an interesting look at how people overcome personal turmoil – but maybe avoid it if you are on your first ever couples holiday!4. Get a view from the topDubrovnik looks fantastic from most angles but a trip up to the top of Mount Srd via cable car will allow you to see the old city in its entirety, along with several of the nearby islands in the middle of the turquoise blue Adriatic ocean. There is also a fantastic coffee shop where can have a refreshment while taking in one of the most iconic views in Eastern Europe. Read more: 10 of the world’s most beautiful places in pictures9. See Zadar’s street installationsPast and present collide most obviously in the city of Zadar, a good alternative for those not willing to tackle the crowds in Dubrovnik or Split. The old town sits on a peninsula and is jam packed with medieval churches and roman ruins to explore. Some of its more modern and quirky attractions include the Sea Organ (an art installation that transforms waves into melodies) and the Sun Salutation (a circle set into the pavement that produces a light show, creating a visualisation of the Sea Organ’s melody).Read more: In pictures: where to see the world’s best street artFind flights to Zadar10. Explore Stari GradStari Grad is Croatia’s oldest town. People first settled here in 384b.c – the same year that Aristotle was born if you need some context. Situated on the popular island of Hvar, this pretty town is an excellent escape from the nightlife and vibrancy of Hvar town. 5. Walk Dubrovnik’s city wallsThe walled city of Dubrovnik is perhaps best explored from its… well… walls. On one side you’ll be dazzled by views of the surrounding cliffs and ocean before a few steps over to the other side of the walk way will leave you equally impressed by close up views of Dubrovnik’s world famous baroque buildings and marble streets. It’ll take you the guts of an hour to walk around the old city and is best done in the morning or late afternoon when the floods of tourists and Game of Thrones enthusiasts have dispersed and you can enjoy a bit of tranquillity.Read more: 29 amazing Game of Thrones locations: in picturesFind flights to Dubrovnik6. Hop around the Elafiti IslandsPerfect for those with itchy feet, the most memorable way to see Croatia is to hop around its islands of which there are over one thousand. With most of the habited islands having daily ferries from the mainland it is easy to explore these vast and varied paradises. We recommend the Elafiti islands, a group of six islands along with several islets where you can explore quaint fishing towns and relax by quiet swimming spots. You can organise a day trip from Dubrovnik’s Old Harbour to the three most popular in the archipelago – Koločep, Lopud and Šipan. Want to know more about Eastern Europe? Check these out**:**8 great places to visit in the Balkans7 beautiful places to visit in SloveniaSarajevo: An Insider’s GuideSkyscanner is the world’s travel search engine, helping your money go further on flights, hotels and car hire.ReturnOne wayMulti-cityFromAdd nearby airports ToAdd nearby airportsDepart14/08/2019Return21/08/2019Cabin Class & Travellers1 adult, EconomyDirect flights onlySearch flights Maplast_img read more