Spanish Research: Black hole that doesn't emit x-rays discovered near massive star

Trailed intensity image of the two lines constructed from the phase binned spectra. 

Two orbital cycles are displayed for clarity. 

The colour scale indicates counts normalised to the continuum, with the black colour corresponding to 0.98 and the white colour to 1.08 in Fe II and 1.16 in HeII. 

Credit: Nature 

Researchers in Instituto de Astrofísica de Canarias, Universidad de Alicante, Universitat de Barcelona, and Institut de Ciències de l’Espai (IEEC-CSIC), Spain have discovered a black hole that doesn't reveal itself through x-ray radiation thrown off by material that is being sucked into it.

In their paper published in the journal Nature, team members from several research institutions throughout Spain, report that the black hole appears to exist as a companion (binary) to a massive Be star that spins so fast it's surrounded by a gas disk.

I. Negueruela

Up until now, virtually all black holes have been discovered via x-ray radiation signals—as material is pulled in past the point of no return, radiation is flung out into space where it is noted by space scientists here on Earth.

In this new effort, the research team was able to identify the black hole because of its behaviour, rather than its signature.

Many Be stars have been found to have companions—most of the time they are supernova remnants (neutron stars) but never before has a Be star been found to have a black hole as a companion.

The star, named MWC 656 is really big—approximately 10 to 16 times as massive as our sun. It spins really fast too (approximately 671,000 mph) which the researchers say, explains why the black hole next to it doesn't emit any radiation.

J. Casares

They suggest that because the star is spinning so fast, it casts gas into a disk surrounding its equator which in turn is cast off towards the black hole, but rather than being pulled in, the gas joins an accretion disk that surrounds the "mouth" of the black hole, moving so fast (due to the angular momentum of the gas cast off from the star) that it can't be pulled in. Thus the disk simply continues to grow larger.

The black hole is pretty big too (approximately 3.8 to 6.9 more massive than our sun) which likely puts it in the category of stellar mass black holes—those that come into existence when a star runs out of fuel.

The discovery of the "silent" black hole suggests that many more like it might exist, which will undoubtedly lead researchers to look for more, now that they know what to look for.

More information: A Be-type star with a black-hole companion, Nature 505, 378–381 (16 January 2014) J. Casares, I. Negueruela, M. Ribó, I. Ribas, J. M. Paredes, A. Herrero & S. Simón-Díaz DOI: 10.1038/nature12916

CHINA: Stench of Air Pollution Soars unabated

Residents of Beijing and many other cities in China were warned to stay inside in mid-January 2013 as the nation faced one of the worst periods of air quality in recent history.

The Chinese government ordered factories to scale back emissions, while hospitals saw spikes of more than 20 to 30 percent in patients complaining of respiratory issues, according to news reports.

At the time that this Jan. 14 image was taken by satellite, ground-based sensors at the U.S. Embassy in Beijing reported PM2.5 measurements of 291 micrograms per cubic meter of air.

Fine, airborne particulate matter (PM) that is smaller than 2.5 microns (about one thirtieth the width of a human hair) is considered dangerous because it is small enough to enter the passages of the human lungs.

Most PM2.5 aerosol particles come from the burning of fossil fuels and biomass (wood fires and agricultural burning). The World Health Organization (WHO) considers PM2.5 to be safe when it is below 25.

Also at the time of the image, the air quality index (AQI) in Beijing was 341. An AQI above 300 is considered hazardous to all humans, not just those with heart or lung ailments. AQI below 50 is considered good.

On January 12, the peak of the current air crisis, AQI was 775 the U.S Embassy Beijing Air Quality Monitor—off the U.S. Environmental Protection Agency scale—and PM2.5 was 886 micrograms per cubic meter.

› View image comparisons with annotations.

Image Credit: NASA/Terra - MODIS

Scottish Mullite: Silicate Material That Can Cut Diesel Pollution

Platinum, a rare and expensive metal, is currently used in diesel engines to try to control the amount of pollution released into the air.

Scientists have now developed a new material that is much more effective than platinum in reducing pollution. University of Texas at Dallas scientists have found that oxide mullite could reduce pollution up to 45 percent compared to platinum crystals.

Mullite or porcelainite is a rare silicate mineral of post-clay genesis, They claim that mullite is less expensive to produce compared to platinum crystals.

Mullite was first described in 1924 for an occurrence on the Isle of Mull, Scotland. It occurs as argillaceous inclusions in volcanic rocks in the Isle of Mull and also with emerylike rocks in Sithean Sluaigh, Scotland.

"Many pollution control and renewable-energy applications require precious metals that are limited - there isn't enough platinum to supply the millions and millions of automobiles driven in the world," said Dr Kyeongjae "K J" Cho, professor at the University of Texas.

"Mullite is not only easier to produce than platinum, but also better at reducing pollution in diesel engines."

Diesel engines give higher fuel efficiency compared to gasoline but produce more nitric oxide (NO) and nitrogen dioxide (NO2), which are quite harmful to human health.

Recently, the World Health Organisation (WHO) upgraded the classification of diesel engine exhaust as carcinogenic in humans, putting it in the same category as cigarette smoke and asbestos.

Countries throughout the world have drafted guidelines to reduce diesel air pollution in the next decade.

The new material developed by scientists could be a new cheap and effective way to reduce pollution.

The discovery was made while analysing the chemical components of mullite.

The team used advanced computer modelling techniques to analyse how different forms of the mineral interacted with Oxygen (O) and Nitrous Oxide (NOx).

The study revealed that the oxide mullite reduces pollution up to 45 percent compared to platinum crystals.

"Our goal to move completely away from precious metals and replace them with oxides that can be seen commonly in the environment has been achieved," Dr Cho said.

"We've found new possibilities to create renewable, clean energy technology by designing new functional materials without being limited by the supply of precious metals."

NASA Video Shows Increase in Global Warming

Global temperatures have warmed significantly since 1880, the beginning of what scientists call the "modern record." 

At this time, the coverage provided by weather stations allowed for essentially global temperature data. 

As greenhouse gas emissions from energy production, industry and vehicles have increased, temperatures have climbed, most notably since the late 1970s. 

In this animation of temperature data from 1880-2011, reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average. 

(Data source: NASA Goddard Institute for Space Studies. Visualization credit: NASA Goddard Space Flight Center Scientific Visualization Studio)

The global average surface temperature in 2011 was the ninth warmest since 1880, according to NASA scientists. The finding continues a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since the year 2000.

NASA's Goddard Institute for Space Studies (GISS) in New York, which monitors global surface temperatures on an ongoing basis, released an updated analysis that shows temperatures around the globe in 2011 compared to the average global temperature from the mid-20th century.

The comparison shows how Earth continues to experience warmer temperatures than several decades ago. The average temperature around the globe in 2011 was 0.92 degrees F (0.51 C) warmer than the mid-20th century baseline.

"We know the planet is absorbing more energy than it is emitting," said GISS Director James E. Hansen. "So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record."

The difference between 2011 and the warmest year in the GISS record (2010) is 0.22 degrees F (0.12 C). This underscores the emphasis scientists put on the long-term trend of global temperature rise. Because of the large natural variability of climate, scientists do not expect temperatures to rise consistently year after year. However, they do expect a continuing temperature rise over decades.

The first 11 years of the 21st century experienced notably higher temperatures compared to the middle and late 20th century, Hansen said. The only year from the 20th century in the top 10 warmest years on record is 1998.

Higher temperatures today are largely sustained by increased atmospheric concentrations of greenhouse gases, especially carbon dioxide. These gases absorb infrared radiation emitted by Earth and release that energy into the atmosphere rather than allowing it to escape to space. As their atmospheric concentration has increased, the amount of energy "trapped" by these gases has led to higher temperatures.

While average global temperature will still fluctuate from year to year, scientists focus on the decadal trend. Nine of the 10 warmest years since 1880 have occurred since the year 2000, as the Earth has experienced sustained higher temperatures than in any decade during the 20th century. As greenhouse gas emissions and atmospheric carbon dioxide levels continue to rise, scientists expect the long-term temperature increase to continue as well. (Data source: NASA Goddard Institute for Space Studies. Image credit: NASA Earth Observatory, Robert Simmon)

The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.

The temperature analysis produced at GISS is compiled from weather data from more than 1,000 meteorological stations around the world, satellite observations of sea surface temperature and Antarctic research station measurements.

A publicly available computer program is used to calculate the difference between surface temperature in a given month and the average temperature for the same place during 1951 to 1980. This three-decade period functions as a baseline for the analysis.

The resulting temperature record is very close to analyses by the Met Office Hadley Centre in the United Kingdom and the National Oceanic and Atmospheric Administration's National Climatic Data Center in Asheville, N.C.

Hansen said he expects record-breaking global average temperature in the next two to three years because solar activity is on the upswing and the next El Niño will increase tropical Pacific temperatures. The warmest years on record were 2005 and 2010, in a virtual tie.

"It's always dangerous to make predictions about El Niño, but it's safe to say we'll see one in the next three years," Hansen said. "It won't take a very strong El Niño to push temperatures above 2010."

Satellite observes spatiotemporal variations in mid-upper tropospheric methane over China

To understand the profile of methane in China and provide data for validation of satellite products, Fourier Transform Infrared Spectroscopy (FTIR) measurements were made at a ground-based hyperspectral remote sensing laboratory at the National Satellite Meteorological Center.

Atmospheric methane (CH4), one of the main greenhouse gases, has increased dramatically worldwide since the pre-industrial era. However, much work is needed to build on intermittent and scattered observations since the 1960s and systematic study since the 1980s.

Since 1983, the World Meteorological Organization (WMO) has coordinated global in-situ measurement of methane. Quantification of methane emissions still has large uncertainties, mainly because of undersampling over most regions of the globe by surface observation networks.

In particular, spatiotemporal variations of mid-upper tropospheric methane in China are not well understood, because of limited in-situ measurements.

Dr. ZHANG Xingying and his group at the National Satellite Meteorological Center of the China Meteorological Administration tackled this problem using satellite observations.

Using Atmospheric Infrared Sounder (AIRS) methane data from 2003 to 2008, they revealed spatiotemporal variations of mid-upper tropospheric methane in China.

Their study shows that in the mid troposphere, a center of low CH4 concentration is located over western China, attributable to minimal industrial and agricultural activity. The lowest CH4 mixing ratio in the upper troposphere is over southern China, related to atmospheric transport from the ocean.

A seasonal cycle of methane has been discovered. One peak in summer and the other in winter over eastern, northeastern and northwestern China. Only one peak (in summer) occurs over southern and western China.

Before 2007, CH4 mixing ratio was nearly stable. The average mixing ratio during the last 6 years over major northern hemispheric countries is similar.

However, there has been a significant increase in tropospheric CH4 concentrations after 2007 in most northern hemispheric areas, with slightly larger increases over China.

Dr. ZHANG Xingying has stated that the trend of CH4 based on satellite observation is still somewhat uncertain, because of the short, 6-year dataset. More satellite data of higher quality are needed for further trend analysis.

To understand the profile of methane in China and provide data for validation of satellite products, Fourier Transform Infrared Spectroscopy (FTIR) measurements were made at a ground-based hyperspectral remote sensing laboratory at the National Satellite Meteorological Center.

A Bruker FTIR instrument (IFS 120 M, made in Ettlingen, Germany) with 0.008 cm-1 spectral resolution, was used for observations. Several years of data have been collected.

Implementation and promotion of this work will publicize methane spatiotemporal variations and their potential sources. In so doing, informed efforts may be mounted to reduce methane emission and resulting global climate change.

The National Satellite Meteorological Center manages satellite climate products in China. Two payloads for greenhouse gas monitoring are in development for the next satellite. One of the payloads is similar to AIRS for mid-upper tropospheric greenhouse gases.

The other is for low tropospheric greenhouse gases, and uses a near-infrared (NIR) spectrometer. Meanwhile, more in-situ measurements have been carried out in China for more detailed investigation of greenhouse gases.

Dr. XIONG Xiaozhen, an expert from NOAA, is in charge of AIRS methane product retrieval. He believes that this study is the first to use satellite data for analyzing mid-upper tropospheric methane over China, and represents important step in the study of climate change.

Hong Kong's carbon Footprint second highest in World

Hong Kong's carbon footprint second highest in world: report

Hong Kong (AFP) Nov 30, 2009
Hong Kong has the second highest carbon footprint per capita in the world, due to the city's high consumption patterns and large volume of imports according to a survey released in Norway.

The study, conducted by a group of Norway-based scientists, compared the greenhouse emissions of 73 economies and found Hong Kong with a per capita footprint of 29 tonnes per year, second only to Luxembourg's 33 tonnes.

The results prompted calls for Hong Kong, a city of seven million, to strengthen measures to cut its greenhouse gas emissions.

Titled "Carbon Footprint of Nations: A Global, Trade-linked Analysis", the research paper was published in the Environmental Sciences and Technology Journal in June. But the results did not come to the public's attention until they were reported by the daily South China Morning Post on Monday.

Using global data from 2001, the study put Hong Kong's carbon footprint among the highest, larger than the United States' 28.6 tonnes, Singapore's 24.1 tonnes and United Kingdom's 15.4.

Most of the environmental impact comes from the manufacturing and transportation of imported goods, with only 17 per cent of emissions from domestic activities.

The figure is significantly higher than one released by the Hong Kong Environmental Protection Department -- 6.7 tonnes per capita -- which took into account local emissions, such as from transport and power generation, but excludes emissions from the production of imported goods.

A spokeswoman for the Environmental Protection Department declined to comment on the statistics but said the government abides by international guidelines on greenhouse gas emissions.

Bill Barron, a professor from the Hong Kong University of Science and Technology's Institute for the Environment, said the government needs to tackle the problem.

"Hong Kong is an economy that is extremely dependant on trade. Therefore the city is tied to the ecological footprints that these imports make," Barron said.

He added that the government is avoiding its responsibility to reduce greenhouse emissions.

Pollution has become an increasing health and economic problem for the financial hub in recent years.

Emissions from the southern Chinese factory belt over Hong Kong's northern border have combined with local emissions from power generators and transport to park a thick haze over the city for most of the year.