(Visited 334 times, 1 visits today)FacebookTwitterPinterestSave分享0 This entry continues yesterday’s news about scientific integrity.Replication CrisisReplication failures in psychology not due to differences in study populations (Nature). Psychologists cannot just blame their replication failures on differences in the study groups. “Half of 28 attempted replications failed even under near-ideal conditions.”Researcher discusses the the science replication crisis (Phys.org). “If there’s a central tenet that unites all of the sciences, it’s probably that scientists should approach discovery without bias and with a healthy dose of skepticism,” this article begins. “The idea is that the best way to reach the truth is to allow the facts to lead where they will, even if it’s not where you intended to go.” Sounds like a great idea. When do they start?The Call for OpennessTime to break academic publishing’s stranglehold on research (New Scientist). Publishers have a vested interest in their power to decide what gets communicated as science. “Science journals are laughing all the way to the bank, locking the results of publicly funded research behind exorbitant paywalls,” this article complains. “A campaign to make content free must succeed.”Scientific impact increases when researchers publish in open access and international collaboration (PLoS One). This journal may have a bias, since it is an open-access publication. One can read it and check their conclusions against the data.No more first authors, no more last authors (Nature). Scientists desire to be first authors, so that their papers can be cited by their names, as in ‘Adams et al.’ Often, too, the last author is the most prestigious one in the group. In the day of increasing collaboration, this practice does more harm than good.Funders flesh out details of Europe’s bold open-access plan (Nature). If Europe’s ‘Plan S’ catches on, it will bring sunshine into science, allowing all the stakeholders – including the public – to see the research. Understandably, the journals behind paywalls stand to lose money big time. This article is fair, but is quick to point out problems the plan might create. See also Science Magazine‘s take on this development.Related SubjectsWhy academia reminds me of my childhood cult (Nature). In its daily briefing, Nature noted a piece in the Washington Post about Andrew Marzoni, who ‘blew off’ a pseudo-Christian cult in his childhood only to find similar methods of mind control in academia. “No one says it aloud, but every graduate student knows: This is the price you pay for a chance to enter the sanctum of the tenure track. Follow the leader, or prepare to teach high school.”Should All Nobel Prizes Be Canceled for a Year? (Live Science). Prizes are shiny objects the media loves, but they take eyes off of what science should be about: a search for truth. The quest for a prize can corrupt motives, and prizes often leave out worthy individuals. Since the rules only allow three winners per category, group discoveries suffer. And what about the other sciences that the Nobel Committee left out? Why should a few political leftists in Sweden be the determiners of who has made a “worthy” discovery? These are a few reasons to ask whether Nobel Prizes should not just be canceled for a year, but forever.The Moral Machine Experiment (Nature). Researchers in this paper claim to have made progress in defining morality policies for artificial intelligence, particularly moral dilemmas that autonomous vehicles will face. Obviously, “moral” cannot be defined by the scientific method. These authors truck their assumptions about morality into their work.Scientists struggle with confusing journal guidelines (Nature). Even if a scientist wants to do the right thing, how can he or she know what it is? This is especially a problem for researchers who do not speak English.To dispel myths, redirect the belief, study says (Medical Xpress). The very title of this article should raise red flags. Who granted scientists the right to decide how to change other people’s beliefs, especially when they have issues of integrity and fake science themselves? Falling for bad scientific ideas is undoubtedly a problem for many people lacking discernment, but when scientists become arbiters of effective methods for changing people, their methods could feed dictatorial regimes who want to enforce conformity.Science knowledge shifted along religious, political affiliations (Phys.org). Two social scientists at the University of Nebraska at Lincoln find that biases are hard to eradicate from research. Another sociologist says, “”Scientists hope that science is apolitical,” she said. “But we take in and code information based on our perspectives – including political ideology and religious beliefs.”First law of leadership: be human first, scientist second (Nature). Alison Antes gives social advice to researchers about building relationships in the lab. But to an evolutionist, what does it mean to “be human” if not to use cutthroat tactics for survival? She borrows Christian ethics, like “model desired behavior,” without attribution to the Apostle Paul, who said, “What you have learned and received and heard and seen in me—practice these things” (Philippians 4:9). Her article does illustrate, however, that science is done by humans who need to build character.Rogue science strikes again: the case of the first gene-edited babies (G. Owen Schaefer, The Conversation). The media are abuzz with ethical judgments about a Chinese researcher’s claim to have edit the genes of two baby girls. Boardman and O’Neill, one a geneticist and the other a social scientist, weigh in on the subject in another piece on The Conversation. The development opens up a huge can of worms, all admit, and many say further research of this type should be outlawed.Shock greets claim of CRISPR-edited babies (Science Magazine).Can scientists use gene editing for disease prevention but not human enhancement? (Phys.org).Editorial: The (somewhat obvious) ethical problems with creating gene-edited babies (The Times Editorial Board via Phys.org)Notice that science cannot be neutral here. Science “can” do things that it “should not” do. Read Wesley J. Smith’s comments on this development at Evolution News.One thing Big Science needs to do is get out of politics. We have collected a large number of new examples of political bias in scientific papers and articles that we will be sharing soon. Today’s entry provides foundation for questioning Big Science’s ability to be unbiased.Scientist, research thyself.Recommended Resource: J. P. Moreland’s new book Scientism and Secularism: Learning to Respond to a Dangerous Ideology puts into print many of Moreland’s ideas on philosophy of science (his PhD specialization), extending them since his 1999 book Christianity and the Nature of Science. Hear an interview about the book on ID the Future. He defines scientism, and shows three major reasons it is indefensible as a philosophy or way of knowing. When interviewer Michael Keas (PhD in history of science) says that historians and philosophers need to work together, Moreland gives the following response that is worth sounding throughout the churches of America.We really have to alert the public. Youth leaders, our Christian school teachers, parents that are raising their kids, we need to alert them to the fact that scientism is really at the bottom of the turmoil we’re facing at culture. Barna did a study recently and found that the six reasons that people are leaving Christianity for atheism are all intellectual reasons, and a couple of them deal with the inability of the church to help believers know how to relate their theology and their Biblical beliefs to science – and science trumps! And so we have retreated to “faith,” and the culture has become morally relativistic because the major things about religion and politics and ethics can’t be known scientifically. So what scientism has done is funded relativism in culture and blind faith commitments in Christianity. And that isn’t sustaining people when they get out of our youth groups and go to college or go into the workforce and meet thoughtful, intelligent unbelievers who will say things like, “Well, prove it– you can’t prove Christianity scientifically, so I don’t have to listen to you.” They don’t know what to say. And so my book is an attempt to do what you’re calling us to do, and that is to work together with our Christian leaders and parents to give them a tool they can learn about themselves and teach our kids and inoculate them responsibly so that they’re not sucked into a culture of scientism.When you tie these thoughts into what you have just read above in Nature and Science about Big Science’s own admissions of bias and unreliability, we should ask: why should anyone bow to the false idol of scientism? Integrity is the foundation of trust for any claim by any person in any field, not appeal to some “method” that scientists self-righteously assert protects them from error.How leading experts can be fooled.Another helpful resource is Jerry Bergman’s recent book Evolution’s Blunders, Frauds and Forgeries (2017). When you learn about how leading scientists fell for fraudulent claims in the past (like Piltdown Man and much more), you begin to realize that scientists are just as prone to error as anyone, especially when their Darwinian ideology motivates their research.[What Piltdown hoaxes are floating about these days, to be exposed some future day? We can suggest several candidates.]
A Comprehensive Guide to a Content Audit Facebook is Becoming Less Personal and More Pro… Tags:#Facebook#Google#Microsoft#web mike melanson According to Craddock, the response to the feature has been good since it was first announced last September. “Since announcing the availability of Facebook chat in Messenger worldwide two weeks ago, nearly 2.5 more million people connected their Facebook accounts to Windows Live, bringing the total to over 20 million customers,” writes Craddock. “And with three out of four Hotmail customers using Facebook, we expect that many more people will want to take advantage of this feature, now that it’s available from your Hotmail inbox.”If you’re a Hotmail user and haven’t yet tried out the feature, all you need to do is connect your Facebook account to Windows Live and check the box for “Chat with my Facebook friends in Messenger.” Hotmail may have three times as many users as Twitter, but it’s looking for something that may not be as easily quantifiable – the cool factor of Google’s Gmail. That’s something that Microsoft has been working on for a while now, with a full redesign of its email client last year. Today, the company announced that it’s adding another bit of cool to its 350 million member email system – full chatting capabilities with Facebook’s 600 million member network worldwide.Microsoft first announced Facebook chat in Hotmail as a part of a number of updates last September, but the feature was only activated in the U.S., U.K., France, Brazil, Germany, and Russia. Today, the company announced that it would be available worldwide, wherever both Hotmail and Facebook were accessible. Hotmail program manager Dick Craddock the company’s little brother syndrome when it comes to Gmail in the announcement. “While Gmail beat us to bringing their own chat into the inbox,” writes Craddock, “we have now gone a step further and brought both our own chat and Facebook chat into your inbox.” Take that Gmail. Being serious, though, most integrations like this have one exciting thing in common – they’re good for the end-user. The feature lets users on both ends – those logged into Facebook and those on Hotmail – communicate seamlessly with each other. Gmail only has Gtalk and no Facebook. Related Posts The Dos and Don’ts of Brand Awareness Videos Guide to Performing Bulk Email Verification
Only teams with a playoff swing of at least 2 percentage points based on the game outcome shown Only teams with a playoff swing of at least 2 percentage points based on the game outcome shown Only teams with a playoff swing of at least 2 percentage points based on the game outcome shown With three weeks left in the NFL season, 11 playoff spots are open. That means that most of the remaining 48 games — save some stinkers like 49ers-Rams — will make some impact on the postseason. What are this week’s biggest games?For the last month, we’ve been using the model behind our 2016 NFL predictions to calculate how much each team’s playoff chances “swing” depending on the outcome of each game. For example, we currently give the Green Bay Packers a 31 percent chance of making the playoffs. If they beat Chicago this week, we project those chances will increase to 40 percent (independent of other games). If they lose, their chances drop to 11 percent.1Our NFL predictions are based on 100,000 simulations of the rest of the season and are updated after every game ends. In the simulations in which Green Bay beats Chicago, they make the playoffs 40 percent of the time. In simulations where they lose, they make the playoffs 11 percent of the time. But it’s unlikely that Green Bay’s playoff probabilities will be exactly 40 percent or exactly 11 percent at the end of Week 15, because the team’s chances depend on the outcome of several games, not just their own. The Packers’ current chances are much closer to 40 percent than to 11 percent because they are much more likely to beat the Bears (69 percent) than lose to them (31 percent). That’s a 29 percentage point swing! By doing this same math for every matchup and factoring in how each team’s resulting record will affect others’ playoff odds, we can find out which games are the most impactful.But “most impactful” only tells part of the story. Let’s say you’re a Green Bay fan, or a fan of any other team on the playoff bubble. Which set of outcomes would help the most this week? To help answer this question, we’ve updated our predictions page to allow you to pick the outcomes of every game for Weeks 15 through 17, so you can see how each matchup affects every team’s probabilities. In the “best case” scenario I could find for the Packers, they’d beat the Bears, but also Dallas would beat Tampa Bay, San Francisco would beat Atlanta, the New York Giants would beat Detroit, Indianapolis would beat Minnesota, and Carolina would beat Washington.With these six outcomes, Green Bay’s playoff chances rise to 58 percent. Go create your own scenarios! The five biggest games of Week 15 are below. Detroit84987127– Tennessee2425232– AFFECTED TEAMCURRENTIF NE WINSIF DEN WINSSWING Washington4649445– Minnesota1922174– Minnesota1923176– Buffalo24—4– Baltimore27322110– Atlanta9193894– Atlanta9189912– 1. Detroit (9-4) vs. N.Y. Giants (9-4) — 93 total ‘swing’ points Indianapolis3142– Denver54%33%78%44– We’re down to one wild card slot in the AFC. While neither Oakland nor Kansas City has officially clinched the postseason, we currently give both teams a greater than 99 percent chance, and only one of them (probably the Chiefs) will make it in as the AFC West champion. Denver is still clinging to that second wild card spot, but their loss to the Titans in Week 14 set their chances back. They’ll now face a brutal end-of-season schedule, facing New England, Kansas City and Oakland. 4. Carolina (5-8) vs. Washington (7-5-1) — 88 total ‘swing’ points 2. New England (11-2) vs. Denver (8-5) — 90 total ‘swing’ points CHANCE OF MAKING PLAYOFFS CHANCE OF MAKING PLAYOFFS Green Bay3127347– Tampa Bay54%85%42%43– N.Y. Giants7570778– 5. Tennessee (7-6) vs. Kansas City (10-3) — 72 total ‘swing’ points Atlanta9192893– Green Bay3135287– CHANCE OF MAKING PLAYOFFS Detroit8482853– AFFECTED TEAMCURRENTIF TB WINSIF DAL WINSSWING Miami27361521– Only teams with a playoff swing of at least 2 percentage points based on the game outcome shown 3. Tampa Bay (8-5) vs. Dallas (11-2) — 88 total ‘swing’ points Tampa Bay5457516– The Buccaneers have won five straight and control their own playoff destiny. Dallas is guaranteed a postseason slot, but if you choose an outcome to this game on our new NFL predictions page you’ll see that a win improves their chance of a first-round bye to 99 percent, and a loss drops them to 80 percent. This makes a huge impact on their Super Bowl probabilities, so the Cowboys — who are at risk of dipping into a quarterback controversy — have quite a bit to play for here. Only teams with a playoff swing of at least 2 percentage points based on the game outcome shown N.Y. Giants75%54%93%39– CHANCE OF MAKING PLAYOFFS AFFECTED TEAMCURRENTIF TEN WINSIF KC WINSSWING Houston75537926– Washington46375013– CHANCE OF MAKING PLAYOFFS The Lions had their eighth fourth-quarter/overtime comeback of the season on Sunday, and now somehow find themselves in contention for a first-round bye. But Detroit’s remarkable season has come against a pretty weak schedule, and they’ll have to wrap up the year against the Giants, Cowboys and Packers. The winner of this game would be nearly assured of a playoff spot, but the loser will be in decent shape. Green Bay, which is in the hunt for the NFC North, is rooting for the Giants. Tampa Bay, Washington, Atlanta and (somewhat surprisingly) Minnesota would prefer a Detroit win to improve their wild card standing. AFFECTED TEAMCURRENTIF DET WINSIF NYG WINSSWING Detroit8486824– Tennessee24%53%19%34– The Panthers’ playoff chances are more or less nil, but they have the opportunity to play spoiler three games in a row against Washington, Atlanta and Tampa Bay.2You may have noticed that Tampa Bay-Dallas and Carolina-Washington both have a “swing” total of 88 points. That number is rounded, but we use a little more precision when we determine the rankings, and Tampa Bay-Dallas is the (very slightly) more impactful game. Washington would miss the playoffs if the season ended today and would fall to having just a 1-in-5 chance of making them with a loss here. Washington46%22%64%43– Denver5452542– Pittsburgh8991874– N.Y. Giants75827012– Tampa Bay5458508– Green Bay31243310– Minnesota1914217– AFFECTED TEAMCURRENTIF CAR WINSIF WAS WINSSWING The Titans also control their own destiny! Wins against the Chiefs, Jaguars and Texans in the final three weeks will leave the Titans with a 10-6 record and an AFC South title. And yet, we give them just a 24 percent chance of making the playoffs. One reason for this is that this week’s matchup in Kansas City, where the Titans will be major underdogs by any measure. But it’s also possible that our ratings are understating the Titans’ overall strength. Elo carries over from season to season, and while most teams have shaken whatever effect 2015 had on their rating, Tennessee started in such a huge hole — their 2015 end-of-season rating was 1272 — that we’re still rating them as a significantly below-average team. A win in Kansas City would send their Elo, and their playoff chances, skyrocketing.CORRECTION (Dec. 15, 2:13 p.m.): A previous version of this article misstated the best-case scenario for the Packers in Week 15. In that scenario, the best outcome for Green Bay would be the Giants beating the Lions, not the other way around.Check out our latest NFL predictions.
Facebook Twitter Google+LinkedInPinterestWhatsApp Facebook Twitter Google+LinkedInPinterestWhatsAppKINGSTON, Feb. 16 (JIS): State Minister in the Science, Technology, Energy and Mining Ministry, Hon. Julian Robinson, says the opening of the latest branch in the Popeyes restaurant franchise represents confidence in the growing economy. “Any new business in this economic environment is important. Popeyes employs about 20 persons and that is 20 new jobs in an economy, which is critical to (its) overall growth and development,” the State Minister said. Mr. Robinson was speaking at the restaurant’s official opening at the Cross Roads Shopping Centre, in Kingston, on February 16. The State Minister, who is also Member of Parliament for St. Andrew South Eastern, the area in which the restaurant is located, hailed the effort of its staff in incorporating locally sourced ingredients in meals. This, he said, is critical as it further enables growth and development of the local economy. Mr. Robinson wished the business continued success and longevity. Meanwhile, Chief Executive Officer (CEO) of Restaurant Associates Limited, Richard Lake, said three more Popeyes are scheduled to be opened across the island by the end of the year. Restaurant Associates are the owners of both Burger King and Popeyes. Mr. Lake also told those in attendance that the business was opened on time and within budget. Following the opening, the State Minister, the CEO and other stakeholders toured the facility. Related Items:Hon. Julian Robinson, popeye restaURANT, Richard Lake Recommended for you Government Continues To Create Environment For Technology And Innovation
Facebook Twitter Google+LinkedInPinterestWhatsAppProvidenciales, TCI, September 9, 2016 – There are no laws in the Turks and Caicos which require the prison or police to inform the public that a violent sex offender has completed prison time. The Governor’s Office is the only entity responding so far to our queries on Robert Jackson, aka Black.Jackson had been incarcerated for a string of violent home invasions, one involving a pregnant woman who was sexually assaulted; that case was from 2008. The Governor’s Office said and I quote:“I can understand the concerns that have been expressed to you. However, Mr Jackson served all of the period that he was committed to prison to serve and was released accordingly. There is no requirement within Prisons Ordinance for any victim or community notification when anyone is released from prison without this being for the purposes of parole. Although it is possible for prisoners to seek voluntary supervision upon release, there is no statutory supervision requirements contained within the Prisons Ordinance.” End quote.The Governor adds that the Police are aware of Mr. Jackson’s release from Her Majesty’s Prison on September 2nd, 2016. Facebook Twitter Google+LinkedInPinterestWhatsApp Related Items:no laws requiring public to be informed when sex offenders are released, police aware of mr. jackson’s release, robert jackson released from prison, sex offender back on streets of TCI
-The district administration on Sunday slapped section 144 in Khagrachhari municipality area from morning to evening to ward off any untoward incident centring a protest programme seeking cancellation of the primary school teachers’ recruitment process.Sushama Unnyan O Durniti Protirodh Committee of the district arranged a rally at Khagrachhari Sadar upazila headquarter in the morning brining allegations of massive corruption in teachers’ recruitment process of primary schools by the district administration.During the rally, the speakers demanded the cancellation of the recruitment process. Otherwise, the district administration office will be besieged, they threatened.Following this, the district administration imposed section 144 starting from 8:00 am to 6:00 pm to maintain law and order situation.However, the committee decided to enforce a hartal on Monday.Section 144 of the Criminal Procedure Code (CrPC) of 1973 empowers an executive magistrate to prohibit an assembly of more than four people in an area.
A survivor of a boat carrying migrants that sunk in the Mediterranean during the night of 9 and 10 May rests at a shelter in the Tunisian coastal city of Zarzis on 11 May, 2019. Photo: AFPA Bangladeshi farmer watched dozens drown beside him in the Mediterranean before “God sent us the fishermen”, who saved him from the cold waters and took him to Tunisia.Ahmed Bilal was one of 16 survivors of the shipwreck, in which an estimated 60 people died on Friday while trying to reach Italy.”I can’t stop myself crying,” said Bilal, who lost two younger relatives in the accident, from a Red Crescent emergency centre in the southern Tunisian coastal town of Zarzis.The 30-year-old said he began his journey to Europe six months ago, flying with three others to Dubai and onwards to Istanbul in Turkey.From there they took another flight to the Libyan capital Tripoli, Bilal said, where they joined around 80 other Bangladeshis and were held in a room in western Libya for three months.”I already thought I would die in Libya,” he said. “We had food only once a day, sometimes less. There was one toilet for 80 people. We could not wash — only our teeth — and we were crying, begging for food.”Medical charity Doctors Without Borders (MSF) estimates 6,000 migrants in Libya are being detained “in conditions that generally fall well below international standards”. Survivors of a boat carrying migrants that sunk in the Mediterranean during the night of 9 and 10 May, gather at a shelter in the Tunisian coastal city of Zarzis on 11 May, 2019. Photo: AFPThe situation has worsened since eastern commander Khalifa Haftar launched an offensive to take Tripoli last month, with more than 450 people killed due to fighting linked to that military campaign, according to the World Health Organization.- ‘I have nothing now’ -Bilal had no idea what he would face when he embarked on the journey from Bangladesh’s Sylhet region, where he had seen villagers with relatives in Europe live a better life.After his family sold their land, the father of two paid a Bangladeshi smuggler nicknamed “Good Luck” around $7,000 (6,230 euros) to arrange the trip.”He said we would have a better life and we believed him. I am sure most of the people he sends die on the way”, said Bilal.He and the other migrants left northwestern Libya on a large boat, before being transferred to a smaller one.Manzour Mohammed Metwella, an Egyptian who was on board, said the boat “started to sink almost immediately.””We swam all night,” said the 21-year-old.Survivors said all the passengers were men, with 51 from Bangladesh, three Egyptians, several Moroccans, Chadians and other Africans.After seeing people drown in front of his eyes, Bilal said he “was losing hope myself, but God sent us the fishermen who saved us.”The fishermen were able to rescue 14 Bangladeshis, one Moroccan, and the Egyptian Metwella.”If the Tunisian fishermen hadn’t seen them, there wouldn’t have been any survivors and we would have never known about this” boat sinking, said Mongi Slim from the Red Crescent.The survivors now have 60 days to decide whether to return home, seek asylum through the United Nations refugee agency, or try their luck in Tunisia.But there is no asylum law in Tunisia and residents are already facing high unemployment and overstretched public services.”We lost so much, I have nothing now,” said Bilal, admitting he still wants to reach Europe to earn money.”But I don’t want to go on the sea like this again, I am done with this risk.”Humanitarian organisations have faced hostility from governments for running rescue missions in the Mediterranean.
GABRIEL C. PÉREZ / KUTDell Seton adopted protocols to reduce opioid overdoses among new moms.Two-thirds of Texas hospitals offering maternity services are taking part in a statewide initiative aimed at reducing maternal mortality.Texas health officials this week kicked off a project called “TexasAIM,” an effort to get hospitals to use a set of protocols referred to as “safety bundles.” The goal is to standardize how doctors in Texas deal with pregnant women who are at risk of common complications during pregnancy or shortly after giving birth.The state plans to tackle hemorrhage, hypertension and opioid abuse first. All three are among the leading causes of maternal deaths in the state.“Our goal is to have as many hospitals participate that want to participate,” says Dr. Manda Hall, the associate commissioner for community health improvement at the Texas Department of State Health Services.So far, Hall says, 168 hospitals have joined TexasAIM – that’s out of the 242 hospitals in the state that offer maternity services.“We know that there is an opportunity here to really make a difference here in Texas as it relates to maternal mortality and severe maternal morbidity,” she says. “So, we are very happy to see the number of hospitals that are here today and participating.”During a meeting in Austin on Monday, hospital leaders from across the state met to discuss how they plan to implement the protocols and what it would look like in their own hospitals.“What it looks like in one hospital may look different in another hospital and that’s OK,” Hall says.That’s especially true because some hospitals already have been using these safety bundles.“We didn’t wait for TexasAIM to come along,” says Dr. John Harkins, a professor at UT Austin’s Dell Medical School and physician with Seton hospitals. “We’ve had these because it is evidence-based, and being an academic teaching center, we were able to get these up and running.”And Harkins says he’s already seeing results.“From my own experience, these things work great,” he says. “They save lives.”A lot of what doctors do is repetitive, Harkins says, and these safety bundles create yet another routine – but this one is backed by science.“Physicians at times are loathe to adopt standardization,” he says. “And you hear things like that, ‘You know, well, each patient you have to treat it like an art, and they are all different’ and that kind of stuff. But in certain things, it’s not an art; it is a science.”Harkins also says there are examples out there in the world of strict routines being safer.“Airline pilots go through the exact same protocols and checklists every single time they land a plane,” he says. “They do the exact same thing every time because they know that that is the safest way to get things done.”Texas health officials say there is evidence that creating protocols in hospitals has curbed maternal deaths in other states. For instance, one of the big drivers behind California’s effort to reduce maternal mortality rates was using new protocols in hospitals. In just four years, the state cut its rate by half. Share
ALMA CO(1–0) observations of NGC 253. Credit: Walter et al., 2017. © 2017 Phys.org More information: Dense Molecular Gas Tracers in the Outflow of the Starburst Galaxy NGC 253, arXiv:1701.05040 [astro-ph.GA] arxiv.org/abs/1701.05040AbstractWe present a detailed study of a molecular outflow feature in the nearby starburst galaxy NGC 253 using ALMA. We find that this feature is clearly associated with the edge of NGC 253’s prominent ionized outflow, has a projected length of ~300 pc, with a width of ~50 pc and a velocity dispersion of ~40 km s^-1, consistent with an ejection from the disk about 1 Myr ago. The kinematics of the molecular gas in this feature can be interpreted (albeit not uniquely) as accelerating at a rate of 1 km s^-1 pc^-1. In this scenario, the gas is approaching escape velocity at the last measured point. Strikingly, bright tracers of dense molecular gas (HCN, CN, HCO+, CS) are also detected in the molecular outflow: We measure an HCN(1-0)/CO(1-0) line ratio of ~1/10 in the outflow, similar to that in the central starburst region of NGC 253 and other starburst galaxies. By contrast, the HCN/CO line ratio in the NGC 253 disk is significantly lower (~1/30), similar to other nearby galaxy disks. This strongly suggests that the streamer gas originates from the starburst, and that its physical state does not change significantly over timescales of ~1 Myr during its entrainment in the outflow. Simple calculations indicate that radiation pressure is not the main mechanism for driving the outflow. The presence of such dense material in molecular outflows needs to be accounted for in simulations of galactic outflows. Explore further (Phys.org)—An international team of astronomers led by Fabian Walter of the Max Planck Institute for Astronomy in Germany has revealed essential properties of a molecular outflow feature in the nearby starburst galaxy designated NGC253. The findings were presented in a paper published Jan. 18 on the arXiv pre-print repository. NGC 253, also known as the Sculptor Galaxy, is an intermediate spiral starburst galaxy in the constellation Sculptor some 11 million light years away. The galaxy is one of the brightest spiral galaxies visible and also one of the dustiest. Due to its proximity and the fact that it is currently undergoing a period of intense star formation, it serves as one of the best laboratories to study starburst–driven galactic–scale winds in detail.NGC 253 is known for the galactic wind emerging from its central area, which carries significant amounts of molecular gas. In order to better characterize this emission, Walter and his team carried out a series of observations between November 2013 and August 2014 utilizing the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. This observational campaign allowed the researchers to uncover crucial properties of the studied molecular outflow.”We present a detailed study of a molecular outflow feature in the nearby starburst galaxy NGC 253 using ALMA,” the paper reads.According to the study, NGC 253’s most prominent outflow feature towards the south has a projected length of about 978 light years, a width of approximately 163 light years, and a velocity dispersion of 40 km s−1. The scientists note that its extent and dispersion are consistent with an ejection from the galaxy’s disk starting about 1 million years ago.The kinematics of the molecular gas in this feature show that the material is approaching us and is also accelerating. However, the astronomers were unable to determine whether or not the molecular mass entrained in the outflow will escape the galaxy, or be recycled to fuel later episodes of star formation. More observations are required to draw final conclusions.”The kinematics of the molecular gas are consistent with accelerating with a velocity gradient of 1 km s−1 pc−1, and at its last measurable point it approaches the escape velocity. (…) More sensitive ALMA observations will trace the outflow even further out, and will shed light on whether or not part of the ejected molecular material will escape the galaxy,” the researchers wrote in the paper.The team also discovered bright tracers of dense molecular gas like HCN, CN, HCO+, CS in the molecular outflow. Moreover, they found that line ratios HCN/CO measured in the outflow are high and consistent with ratios observed in the central starburst region of NGC253 and in other starbursts, while the HCN/CO line ratio in the galaxy’s disk is significantly lower, which is typical for gas in the disks of nearby galaxies. The researchers concluded that this indicates that the dense molecular gas is retaining its properties in the process of its ejection from the central regions into the outflow. 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. Citation: Astronomers uncover properties of a molecular outflow feature in a nearby starburst galaxy (2017, January 24) retrieved 18 August 2019 from https://phys.org/news/2017-01-astronomers-uncover-properties-molecular-outflow.html Starburst to star bust: Astronomers ID suspect behind dearth of high-mass galaxies