Oceans have lost 2 % of oxygen, says study

Washington D.C., Feb 6: An international team of astronomers has found an unusual monster galaxy that existed about 12 billion years ago when the universe was only 1.8 billion years old.

The team of astronomers was led by scientists at the University of California, Riverside.

Dubbed XMM-2599, the galaxy formed stars at a high rate and then died. Why it suddenly stopped forming stars is unclear.

"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultra massive galaxy," said Benjamin Forrest, a postdoctoral researcher in the UC Riverside Department of Physics and Astronomy and the study's lead author.

"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old and then became inactive by the time the universe was only 1.8 billion years old," Forrest added.

The team used spectroscopic observations from the W. M. Keck Observatory's powerful Multi-Object Spectrograph for Infrared Exploration or MOSFIRE, to make detailed measurements of XMM-2599 and precisely quantify its distance.

The study results appear in the Astrophysical Journal.

"In this epoch, very few galaxies have stopped forming stars, and none are as massive as XMM-2599," said Gillian Wilson, a professor of physics and astronomy at UCR in whose lab Forrest works.

"The mere existence of ultramassive galaxies like XMM-2599 proves quite a challenge to numerical models. Even though such massive galaxies are incredibly rare at this epoch, the models do predict them."

"The predicted galaxies, however, are expected to be actively forming stars. What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on. Our results call for changes in how models turn off star formation in early galaxies," the professor stated.

The research team found XMM-2599 formed more than 1,000 solar masses a year in stars at its peak of activity -- an extremely high rate of star formation. In contrast, the Milky Way forms about one new star a year.

"XMM-2599 may be a descendant of a population of highly star-forming dusty galaxies in the very early universe that new infrared telescopes have recently discovered," said Danilo Marchesini, an associate professor of astronomy at Tufts University and a co-author on the study.

"We have caught XMM-2599 in its inactive phase," Wilson said, who led the W. M. Keck Observatory data acquisition
Co-author Michael Cooper, a professor of astronomy at UC Irvine, said this outcome is a strong possibility.

"Perhaps during the following 11.7 billion years of cosmic history, XMM-2599 will become the central member of one of the brightest and most massive clusters of galaxies in the local universe," he said.

"Alternatively, it could continue to exist in isolation. Or we could have a scenario that lies between these two outcomes," he stated.

The study was supported by grants from the National Science Foundation and NASA.

Bengaluru, Jan 17: India’s latest communication satellite GSAT-30 was successfully launched from the Spaceport in French Guiana during the early hours on Friday.

In a press release, ISRO, has stated that the launch vehicle 'Ariane-5 VA-251' was blasted off from Kourou Launch Base, French Ginana at 0230 hours, carrying India’s GSA-30 and EUTELSAT KONNECT for Eutelasat, as per schedule.

The Ariane 5 upper stage in an elliptical Geosynchronous Transfer Orbit.

With a lift-off mass of 3,357 kg, GSAT-30 will provide continuity to operational services on some of the in-orbit satellites.

GSAT-30 derives its heritage from ISRO’s earlier INSAT/GSAT satellite series and will replace INSAT-4A in orbit.

“GSAT-30 has a unique configuration of providing flexible frequency segments and flexible coverage. The satellite will provide communication services to Indian mainland and islands through Ku-band and wide coverage covering Gulf countries, a large number of Asian countries and Australia through C-band," ISRO Chairman Dr K Sivan said.

Dr Sivan also said that “GSAT-30 will provide DTH Television Services, connectivity to VSATs for ATM, Stock-exchange, Television uplinking and teleport Services, Digital Satellite News Gathering (DSNG) and e-governance applications. The satellite will also be used for bulk data transfer for a host of emerging telecommunication applications.”

ISRO’s Master Control Facility (MCF) at Hassan in Karnataka took over the command and control of GSAT-30 immediately after its separation from the launch vehicle. Preliminary health checks of the satellite revealed its normal health.

In the days ahead, orbit-raising maneuvers will be performed to place the satellite in Geostationary Orbit (36,000 km above the equator) by using its onboard propulsion system.

During the final stages of its orbit raising operations, the two solar arrays and the antenna reflectors of GSAT-30 will be deployed. Following this, the satellite will be put in its final orbital configuration.

The satellite will be operational after the successful completion of all in-orbit tests.

Giving each and every app access to personal information stored on Android smartphones such as your contacts, call history, SMS and photos may put you in trouble as bad actors can easily use these access to spy on you, send spam messages and make calls anywhere at your expense or even sign you up for a premium "service", researchers from cybersecurity firm Kaspersky have warned.

But one can restrict access to such information as Android lets you configure app permissions. 

Giving an app any of these permissions generally means that from now on it can obtain information of this type and upload it to the Cloud without asking your explicit consent for whatever it intends to do with your data.

Therefore, security researchers recommend one should think twice before granting permissions to apps, especially if they are not needed for the app to work. 

For example, most games have no need to access your contacts or camera, messengers do not really need to know your location, and some trendy filter for the camera can probably survive without your call history, Kaspersky said. 

While decision to give permission is yours, the fewer access you hand out, the more intact your data will be.

Here's what you should know to protect your data.

SMS: An app with permission to send and receive SMS, MMS, and WAP (Wireless Application Protocol) push messages, as well as view messages in the smartphone memory will be able to read all of your SMS correspondence, including messages with one-time codes for online banking and confirming transactions.

Using this permission, the app can also send spam messages in your name (and at your expense) to all your friends. Or sign you up for a premium "service." You can see and conrol which apps have these rights by going to the settings of your phone.

Calendar: With permission to view, delete, modify, and add events in the calendar, prying eyes can find out what you have done and what you are doing today and in the future. Spyware loves this permission.

Camera: Permission to access the camera is necessary for the app to take photos and record video. But apps with this permission can take a photo or record a video at any moment and without warning. Attackers armed with embarrassing images and other dirt on you can make life a misery, according to Kaspersky.

Contacts: With permission to read, change, and add contacts in your address book, and access the list of accounts registered in the smartphone, an app can send your entire address book to its server. Even legitimate services have been found to abuse this permission, never mind scammers and spammers, for whom it is a windfall.

This permission also grants access to the list of app accounts on the device, including Google, Facebook, and many other services.

Phone: Giving access to your phone means permission to view and modify call history, obtain your phone number, cellular network data, and the status of outgoing calls, add voicemail, access IP telephony services, view numbers being called with the ability to end the call or redirect it to another number and call any number.

This permission basically lets the app do anything it likes with voice communication. It can find out who you called and when or prevent you from making calls (to a particular number or in general) by constantly terminating calls. 

It can eavesdrop on your conversations or, of course, make calls anywhere at your expense, including to pay-through-the-nose numbers, Kaspersky warned.