(Press-News.org) Our Solar System's Milky Way neighborhood just went upscale. We reside between two major spiral arms of our home galaxy, in a structure called the Local Arm. New research using the ultra-sharp radio vision of the National Science Foundation's Very Long Baseline Array (VLBA) indicates that the Local Arm, previously thought to be only a small spur, instead is much more like the adjacent major arms, and is likely a significant branch of one of them.
"Our new evidence suggests that the Local Arm should appear as a prominent feature of the Milky Way," said Alberto Sanna, of the Max-Planck Institute for Radio Astronomy. Sanna and his colleagues presented their findings to the American Astronomical Society's meeting in Indianapolis, Indiana.
Determining the structure of our own Galaxy has been a longstanding problem for astronomers because we are inside it. In order to map the Milky Way, scientists need to accurately measure the distances to objects within the Galaxy. Measuring cosmic distances, however, also has been a difficult task, leading to large uncertainties. The result is that, while astronomers agree that our Galaxy has a spiral structure, there are disagreements on how many arms it has and on their specific locations.
To help resolve this problem, researchers turned to the VLBA and its ability to make the most accurate measurements of positions in the sky available to astronomers. The VLBA's capabilities allowed the astronomers to use a technique that yields accurate distance measurements unambiguously through simple trigonometry.
By observing objects when Earth is on opposite sides of its orbit around the Sun, astronomers can measure the subtle shift in the object's apparent position in the sky, compared to the background of more-distant objects. This effect is called parallax, and can be demonstrated by holding your finger close to your nose and alternately closing each eye. The VLBA's ability to precisely measure very tiny shifts in apparent position allows scientists to use this trigonometric method to directly determine distances much farther from Earth than previously was possible.
The astronomers used this method to measure the distances to star-forming regions in the Milky Way where water and methanol molecules are boosting radio waves in the same fashion that a laser boosts light waves. These objects, called masers, are like lighthouses for the radio telescopes. The VLBA observations, carried out from 2008 to 2012, produced accurate distance measurements to the masers and also allowed the scientists to track their motion through space.
A striking result was an upgrade to the status of the Local Arm within which our Solar System resides. We are between two major spiral arms of the Galaxy, the Sagittarius Arm and the Perseus Arm. The Sagittarius Arm is closer to the Galactic center and the Perseus Arm is farther out in the Galaxy. The Local Arm previously was thought to be a minor structure, a "spur" between the two longer arms. Details of this finding were published in the Astrophysical Journal by Xu Ye and collaborators.
"Based on both the distances and the space motions we measured, our Local Arm is not a spur. It is a major structure, maybe a branch of the Perseus Arm, or possibly an independent arm segment," Sanna said.
The scientists also presented new details about the distribution of star formation in the Perseus Arm, and about the more-distant Outer Arm, which encompasses a warp in our Galaxy.
The new observations are part of an ongoing project called the Bar and Spiral Structure Legacy (BeSSeL) survey, a major effort to map the Milky Way using the VLBA. The acronym honors Friedrich Wilhelm Bessel, the German astronomer who made the first accurate measurement of a star's parallax in 1838.
The VLBA, dedicated in 1993, uses ten, 25-meter-diameter dish antennas distributed from Hawaii to St. Croix in the Caribbean. It is operated from the NRAO's Domenici Science Operations Center in Socorro, NM. All ten antennas work together as a single telescope with the greatest resolving power available to astronomy. This unique capability has produced landmark contributions to numerous scientific fields, ranging from Earth tectonics, climate research, and spacecraft navigation, to cosmology.
###
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.
Earth's Milky Way neighborhood gets more respect
Our own spiral arm moves up from 'spur' to at least 'branch'
2013-06-04
ELSE PRESS RELEASES FROM THIS DATE:
Despite good prognosis, some turn a blind eye to genetic screening
2013-06-04
Even if Australians with newly diagnosed bowel cancer were routinely tested for a genetic predisposition to further cancers, one in three people would still not take the necessary steps to use that information to prevent further disease.
Researchers from UNSW Medicine took the extra step of screening for the hereditary Lynch syndrome in the 2,100 people with colorectal cancer who presented at a number of NSW hospitals* over a three-year period.
Researchers found that a significant number of these people (245) had a bowel cancer with features that suggested Lynch syndrome, ...
Emergency C-section rates are climbing, as is the need for accompanying emergency anesthesia
2013-06-04
There is an increasing need for safe emergency anaesthesia as cases of emergency Caesarean section (CS) continue to rise, say experts speaking at Euroanaesthesia, the annual congress of the European Society of Anaesthesiology (ESA).
Dr Geraldine O'Sullivan (Lead clinician for obstetric anaesthesia, Guy's and St Thomas' NHS Foundation Trust, London, UK) discusses how in the UK between 25-30% of deliveries are by CS, well above the WHO recommended rate of 15% (England 25%, Scotland/Wales 26%, Northern Ireland 30%, UK overall 25%). The 25% overall rate in the UK is made ...
Time limits on welfare can lead to higher mortality rates
2013-06-04
U.S. workfare programs have been praised by some for cutting welfare rolls and improving the economic well-being of families. But little is known about how these policies affected participants' health and mortality. Researchers at Columbia University's Mailman School of Public Health studied enrollees in Florida's Family Transition Program who were given a time limit for welfare benefits and exposed to job training. They were compared to a control group who received traditional welfare benefits. In this randomized controlled trial, the researchers found that participants ...
Smoking, sugar, spirits and 'sin' taxes: Higher price would help health, Mayo Clinic doctors say
2013-06-04
ROCHESTER, Minn. -- Go ye and sin no more -- or pay for it, when it comes to junk food, smoking and consuming alcohol. That's the message from two Mayo Clinic physicians who say raising "sin" taxes on tobacco and alcoholic beverages and imposing them on sugary drinks and fatty foods would lead many people to cut back, improving public health. The article by Michael Joyner, M.D., and David Warner, M.D., appears in the June issue of the journal Mayo Clinic Proceedings.
The physicians contend that much of overall health depends on behavior and is relatively independent of ...
Berkeley Lab researchers unlock mystery behind dormant breast tumor cells that become metastatic
2013-06-04
The long-standing mystery behind dormant disseminated breast tumor cells and what activates them after years and even decades of latency may have been solved. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have identified the microenvironment surrounding microvasculature – the small blood vessels that transport blood within tissues – as a niche where dormant cancer cells reside. When these blood vessels begin to sprout, the new tips produce molecules that transform dormant cancer cells into metastatic tumors.
In ...
Rash decision? New UK coins increase nickel skin allergy risk 4 fold
2013-06-04
In a bid to save £10 million a year the British Treasury is replacing copper–nickel five and ten pence coins with new nickel-plated steel versions. However, while no UK health assessment has taken place, scientists in Sweden have analyzed the allergy risk after the Swedish state bank announced it will reduce traces of nickel in Swedish coinage.
The assessment, published in Contact Dermatitis reveals that the UK public's exposure to nickel allergic reactions will increase four fold. The team analyzes skin exposure and metal release in artificial sweat to find that the ...
Large multi-generational family helps unlock genetic secrets to developmental dysplasia of the hip
2013-06-04
(PHILADELPHIA) – Research from Thomas Jefferson University is laying the foundation for a genetic test to accurately identify hip dysplasia in newborns so that early intervention can be initiated to promote normal development. This research from Jefferson Orthopedics physician-scientists is currently available in the Journal of Bone and Mineralizing Research (JBMR) online at http://onlinelibrary.wiley.com/doi/10.1002/jbmr.1999/abstract.
The researchers studied four generations of a Utah family affected by developmental dysplasia of the hip (DDH) in most generations. ...
12 million bednets and innovative thinking make Ghana malaria partnership a success
2013-06-04
In a report to be released this month, the Promoting Malaria Prevention and Treatment (ProMPT) Project will describe an innovative model for distributing over 12 million mosquito nets to prevent the transmission of malaria in Ghana.
In collaboration with the Ghana Health Service (GHS), and funding from the US Agency for international Development (USAID), the four year long project ensured that millions of households learned how to use nets treated with insecticide to kill mosquitoes, which can transmit malaria. The $20 million project, funded through the United States ...
American, Nepalese children disagree on social obligations with age
2013-06-04
ITHACA, N.Y. – Preschoolers universally recognize that one's choices are not always free – that our decisions may be constrained by social obligations to be nice to others or follow rules set by parents or elders, even when wanting to do otherwise.
As they age, however, American kids are more prone to acknowledge one's freedom to act against such obligations compared to Nepalese children, who are less willing to say that people can and will violate social codes, finds a cross-cultural study by Cornell University development psychologists published in the current issue ...
Researchers discover a new way fish camouflage themselves in the ocean
2013-06-04
Fish can hide in the open ocean by manipulating how light reflects off their skin, according to researchers at The University of Texas at Austin. The discovery could someday lead to the development of new camouflage materials for use in the ocean, and it overturns 40 years of conventional wisdom about fish camouflage.
The researchers found that lookdown fish camouflage themselves through a complex manipulation of polarized light after it strikes the fishes' skin. In laboratory studies, they showed that this kind of camouflage outperforms by up to 80 percent the "mirror" ...
LAST 30 PRESS RELEASES:
Hear here: How loudness and acoustic cues help us judge where a speaker is facing
A unique method of rare-earth recycling can strengthen the raw material independence of Europe and America
Epilepsy self-management program shows promise to control seizures, improve mood and quality of life
Fat may play an important role in brain metabolism
New study finds no lasting impact of pandemic pet ownership on human well-being
New insights on genetic damage of some chemotherapies could guide future treatments with less harmful side effects
Gut microbes could protect us from toxic ‘forever chemicals’
Novel modelling links sea ice loss to Antarctic ice shelf calving events
Scientists can tell how fast you're aging from a single brain scan
U.S. uterine cancer incidence and mortality rates expected to significantly increase by 2050
Public take the lead in discovery of new exploding star
What are they vaping? Study reveals alarming surge in adolescent vaping of THC, CBD, and synthetic cannabinoids
ECMWF - delivering forecasts over 10 times faster and cutting energy usage by 1000
Brazilian neuroscientist reveals how viral infections transform the brain through microscopic detective work
Turning social fragmentation into action through discovering relatedness
Cheese may really be giving you nightmares, scientists find
Study reveals most common medical emergencies in schools
Breathable yet protective: Next-gen medical textiles with micro/nano networks
Frequency-engineered MXene supercapacitors enable efficient pulse charging in TENG–SC hybrid systems
Developed an AI-based classification system for facial pigmented lesions
Achieving 20% efficiency in halogen-free organic solar cells via isomeric additive-mediated sequential processing
New book Terraglossia reclaims language, Country and culture
The most effective diabetes drugs don't reach enough patients yet
Breast cancer risk in younger women may be influenced by hormone therapy
Strategies for staying smoke-free after rehab
Commentary questions the potential benefit of levothyroxine treatment of mild hypothyroidism during pregnancy
Study projects over 14 million preventable deaths by 2030 if USAID defunding continues
New study reveals 33% gap in transplant access for UK’s poorest children
Dysregulated epigenetic memory in early embryos offers new clues to the inheritance of polycystic ovary syndrome (PCOS)
IVF and IUI pregnancy rates remain stable across Europe, despite an increasing uptake of single embryo transfer
[Press-News.org] Earth's Milky Way neighborhood gets more respectOur own spiral arm moves up from 'spur' to at least 'branch'