PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Astronomers discover an oversized black hole population in the star cluster Palomar 5

2021-07-05
(Press-News.org) "The number of black holes is roughly three times larger than expected from the number of stars in the cluster, and it means that more than 20% of the total cluster mass is made up of black holes. They each have a mass of about 20 times the mass of the Sun, and they formed in supernova explosions at the end of the lives of massive stars, when the cluster was still very young" says Prof Mark Gieles, from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and lead author of the paper. Tidal streams are streams of stars that were ejected from disrupting star clusters or dwarf galaxies. In the last few years, nearly thirty thin streams have been discovered in the Milky Way halo. "We do not know how these streams form, but one idea is that they are disrupted star clusters. However, none of the recently discovered streams have a star cluster associated with them, hence we can not be sure. So, to understand how these streams formed, we need to study one with a stellar system associated with it. Palomar 5 is the only case, making it a Rosetta Stone for understanding stream formation and that is why we studied it in detail" explains Gieles. The authors simulate the orbits and the evolution of each star from the formation of the cluster until the final dissolution. They varied the initial properties of the cluster until a good match with observations of the stream and the cluster was found. The team finds that Palomar 5 formed with a lower black hole fraction, but stars escaped more efficiently than black holes, such that the black hole fraction gradually increased. The black holes dynamically puffed up the cluster in gravitational slingshot interactions with stars, which led to even more escaping stars and the formation of the stream. Just before it completely dissolves - roughly a billion years from now - the cluster will consist entirely of black holes. "This work has helped us understand that even though the fluffy Palomar 5 cluster has the brightest and longest tails of any cluster in the Milky Way, it is not unique. Instead, we believe that many similarly puffed up, black hole-dominated clusters have already disintegrated in the Milky Way tides to form the recently discovered thin stellar streams" says co-author Dr. Denis Erkal at the University of Surrey. Gieles points out that in this paper "we have shown that the presence of a large black hole population may have been common in all the clusters that formed the streams". This is important for our understanding of globular cluster formation, the initial masses of stars and the evolution of massive stars. This work also has important implications for gravitational waves. "It is believed that a large fraction of binary black hole mergers form in star clusters. A big unknown in this scenario is how many black holes there are in clusters, which is hard to constrain observationally because we can not see black holes. Our method gives us a way to learn how many BHs there are in a star cluster by looking at the stars they eject.'', says Dr. Fabio Antonini from Cardiff University, a co-author of the paper. Palomar 5 is a globular cluster discovered in 1950 by Walter Baade. It is in the Serpens constellation at a distance of about 80,000 light-years, and it is one of the roughly 150 globular clusters that orbit around the Milky Way. It is older than 10 billion years, like most other globular clusters, meaning that it formed in the earliest phases of galaxy formation. It is about 10 times less massive and 5 times more extended than a typical globular cluster and in the final stages of dissolution.

INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Belowground microbial solutions to aboveground plant problems

Belowground microbial solutions to aboveground plant problems
2021-07-05
Land plants - plants that live primarily in terrestrial habitats and form vegetation on earth - are anchored to the ground through their roots, and their performance depends on both the belowground soil conditions and the aboveground climate. Plants utilize sunlight to grow through the process of photosynthesis where light energy is converted to chemical energy in chloroplasts, the powerhouses of plant cells. Therefore, the amount and quality of light perceived by chloroplasts through light absorbing pigments, such as chlorophyll, is a defining factor in plant growth and health. ...

Hunting and hidden deaths led to 30% reduction in WI wolf population

2021-07-05
MADISON, Wis. -- About 100 additional wolves died over the winter in Wisconsin as a result of the delisting of grey wolves under the Endangered Species Act, alongside the 218 wolves killed by licensed hunters during Wisconsin's first public wolf hunt, according to new research. The combined loss of 313 to 323 wolves represents a decline in the state's wolf population of between 27% and 33% between April 2020 and April 2021. Researchers estimate that a majority of these additional, uncounted deaths are due to something called cryptic poaching, where poachers hide evidence of illegal killings. The findings are the first estimate of Wisconsin's wolf population since the public hunt in February, which ended early after hunters ...

Being clean and hygienic need not impair childhood immunity

2021-07-05
The theory that modern society is too clean, leading to defective immune systems in children, should be swept under the carpet, according to a new study by researchers at UCL and the London School of Hygiene & Tropical Medicine. In medicine, the 'hygiene hypothesis' states that early childhood exposure to particular microorganisms protects against allergic diseases by contributing to the development of the immune system. However, there is a pervading view (public narrative) that Western 21st century society is too hygienic, which means toddlers and children are likely to be less exposed to germs in early life and so become less resistant to allergies. In this paper, published in the Journal of Allergy and Clinical Immunology, researchers point to four significant reasons which, ...

Breakthrough in tissue engineering as 'shape memory' supports tissue growth

2021-07-05
Research published today has demonstrated the viability of 3D-printed tissue scaffolds that harmlessly degrade while promoting tissue regeneration following implantation. The scaffolds showed highly promising tissue-healing performance, including the ability to support cell migration, the 'ingrowth' of tissues, and revascularisation (blood vessel growth). Professor Andrew Dove, from the University of Birmingham's School of Chemistry, led the research group and is the lead author on the paper published in Nature Communications, which characterises the physical properties of the scaffolds, and explains how their 'shape memory' is key to promoting tissue regeneration. ...

More filling? Tastes great? How flies, and maybe people, choose their food

2021-07-05
Flies have discriminating taste. Like a gourmet perusing a menu, they spend much of their time seeking sweet nutritious calories and avoiding bitter, potentially toxic food. But what happens in their brains when they make these food choices? Yale researchers discovered an interesting way to find out. They tricked them. In a study that could also help illuminate how people make food choices, the researchers gave hungry fruit flies the choice between sweet, nutritious food laced with bitter quinine and a less sweet, but not bitter, food containing fewer calories. Then, using neuroimaging, they tracked neural activity in their brains as they made these tough choices. So which won? Calories or better taste? "It depends on how hungry they are," said Michael Nitabach, professor of ...

Structures discovered in brain cancer patients can help fight tumors

2021-07-05
Researchers at Uppsala University have discovered lymph node-like structures close to the tumour in brain cancer patients, where immune cells can be activated to attack the tumour. They also found that immunotherapy enhanced the formation of these structures in a mouse model. This discovery suggests new opportunities to regulate the anti-tumour response of the immune system. Glioma is a deadly brain tumour with a dismal prognosis. One reason why brain tumours are very hard to treat is that our immune system, which is designed to detect and destroy foreign ...

New online calculator can help predict death and end-of-life care needs for older adults

2021-07-05
Although most Canadians die from predictable causes and have health needs that can be met at home, only 20% of people receive a physician home visit in their last year of life. To help understand the changing care needs of older adults as they age and when they might be nearing the end of their lives, a team of researchers developed the Risk Evaluation for Support: Predictions for Elder-Life in the Community Tool (RESPECT). The calculator, which predicts death within 6 months, is based on data from more than 491 000 community-dwelling older adults who used home care in the 6-year period between 2007 and 2013. "The RESPECT calculator allows families and their loved ...

Oncotarget: Epithelial-mesenchymal transitions create endothelial cells and tumor growth

Oncotarget: Epithelial-mesenchymal transitions create endothelial cells and tumor growth
2021-07-05
Oncotarget published "Carcinoma cells that have undergone an epithelial-mesenchymal transition differentiate into endothelial cells and contribute to tumor growth" which reported that the authors investigated whether EMT can confer endothelial attributes upon carcinoma cells, augmenting tumor growth and vascularization. Hypoxic regions, demarcated by HIF-1α staining, exhibited focal areas of E-cadherin loss and elevated levels of vimentin and the EMT-mediator FOXC2. Implantation of MCF-7 cells, co-mixed with human mammary epithelial cells overexpressing the EMT-inducer Snail, markedly ...

Oncotarget: General anesthesia for pancreatic cancer surgery

Oncotarget: General anesthesia for pancreatic cancer surgery
2021-07-05
Oncotarget published "Perioperative changes in the plasma metabolome of patients receiving general anesthesia for pancreatic cancer surgery" which reported that little is known about the impact of anesthesia on the plasma metabolome, although many metabolites have been shown to modulate the function of various immune cells, making it particularly interesting in the context of oncological surgery. In this study longitudinal dynamics in the plasma metabolome during general anesthesia in patients undergoing pancreatic surgery were analyzed. Prospective, observational study with 10 patients diagnosed with pancreatic malignancy and subjected to elective resection surgery under general anesthesia. Plasma metabolites were quantified at ...

Oncotarget: Genome wide DNA methylation landscape reveals glioblastoma's influence

Oncotarget: Genome wide DNA methylation landscape reveals glioblastomas influence
2021-07-05
Oncotarget published "Genome wide DNA methylation landscape reveals glioblastoma's influence on epigenetic changes in tumor infiltrating CD4+ T cells" which reported that whole-genome bisulfite sequencing of tumor infiltrating and blood CD4 T-cell from GBM patients showed 13571 differentially methylated regions and a distinct methylation pattern of methylation of tumor infiltrating CD4 T-cells with significant inter-patient variability. The methylation changes also resulted in transcriptomic changes with 341 differentially expressed genes in CD4 tumor infiltrating T-cells compared to blood. Analysis of specific genes involved in CD4 differentiation and function revealed differential methylation status of TBX21, GATA3, RORC, FOXP3, IL10 and ...

LAST 30 PRESS RELEASES:

Oil spill still contaminating sensitive Mauritius mangroves three years on

Unmasking the voices of experience in healthcare studies

Pandemic raised food, housing insecurity in Oregon despite surge in spending

OU College of Medicine professor earns prestigious pancreatology award

Sub-Saharan Africa leads global HIV decline: Progress made but UNAIDS 2030 goals hang in balance, new IHME study finds

Popular diabetes and obesity drugs also protect kidneys, study shows

Stevens INI receives funding to expand research on the neural underpinnings of bipolar disorder

Protecting nature can safeguard cities from floods

NCSA receives honors in 2024 HPCwire Readers’ and Editors’ Choice Awards

Warning: Don’t miss Thanksgiving dinner, it’s more meaningful than you think

Expanding HPV vaccination to all adults aged 27-45 years unlikely to be cost-effective or efficient for HPV-related cancer prevention

Trauma care and mental health interventions training help family physicians prepare for times of war

Adapted nominal group technique effectively builds consensus on health care priorities for older adults

Single-visit first-trimester care with point-of-care ultrasound cuts emergency visits by 81% for non-miscarrying patients

Study reveals impact of trauma on health care professionals in Israel following 2023 terror attack

Primary care settings face barriers to screening for early detection of cognitive impairment

November/December Annals of Family Medicine Tip Sheet

Antibiotics initiated for suspected community-acquired pneumonia even when chest radiography results are negative

COVID-19 stay-at-home order increased reporting of food, housing, and other health-related social needs in Oregon

UW-led research links wildfire smoke exposure with increased dementia risk

Most U.S. adults surveyed trust store-bought turkey is free of contaminants, despite research finding fecal bacteria in ground turkey

New therapy from UI Health offers FDA-approved treatment option for brittle type 1 diabetes

Alzheimer's: A new strategy to prevent neurodegeneration

A clue to what lies beneath the bland surfaces of Uranus and Neptune

Researchers uncover what makes large numbers of “squishy” grains start flowing

Scientists uncover new mechanism in bacterial DNA enzyme opening pathways for antibiotic development

New study reveals the explosive secret of the squirting cucumber

Vanderbilt authors find evidence that the hunger hormone leptin can direct neural development in a leptin receptor–independent manner

To design better water filters, MIT engineers look to manta rays

Self-assembling proteins can be used for higher performance, more sustainable skincare products

[Press-News.org] Astronomers discover an oversized black hole population in the star cluster Palomar 5