Mysterious faint object detected in the vicinity of a quadruply lensed quasar

first_img More information: Evidence for a Dusty Dark Dwarf Galaxy in the Quadruple Lens MG0414+0534, arXiv:1701.05283 [astro-ph.GA] arxiv.org/abs/1701.05283AbstractWe report the 4σ detection of a faint object with a flux of ~ 0.3 mJy, in the vicinity of the quadruply lensed QSO MG0414+0534 using the Atacama Large Millimeter/submillimeter array (ALMA) Band 7. The object is most probably a dusty dark dwarf galaxy, which has not been detected in either the optical, near-infrared (NIR) or radio (cm) bands. An anomaly in the flux ratio of the lensed images observed in Band 7 and the mid-infrared (MIR) band and the reddening of the QSO light color can be simultaneously explained if we consider the object as a lensing substructure with an ellipticity ~ 0.7 at a redshift of 0.5≲z≲1. Using the best-fit lens models with three lenses, we find that the dark matter plus baryon mass associated with the object is ∼109M⊙, the dust mass is ∼107M⊙ and the linear size is ≳5kpc. Thus our findings suggest that the object is a dusty dark dwarf galaxy. A substantial portion of faint submillimeter galaxies (SMGs) in the universe may be attributed to such dark objects. ALMA 0.88 mm (Band 7) dust continuum images of MG 0414+0534. A faint spot inside a red circle (left) is the “object Y”. Credit: Inoue et al., 2017. Dozens of new ultra-diffuse galaxies discovered in Abell 2744 MG 0414+0534 is a quadruply lensed, radio-loud quasar that showcases a strong sign of anomaly in the flux ratio and reddening in the optical and near-infrared band. This anomaly baffles scientists as its origin is not fully understood yet.In order to reveal more insights into this mysterious anomaly, a team of researchers led by Kaiki Taro Inoue of Kindai University in Japan conducted continuum observations of MG 0414+0534 with ALMA. The observational campaign, which was carried out in June and August 2015, resulted in the discovery of a faint object with a flux of about 0.3 mJy in the vicinity of the quasar. For the purpose of the research, this newly found object was designated “object Y.”According to the paper, “object Y” has an ellipticity of about 0.7 at a redshift between 0.5 and 1.0 and its linear size is at least 16,300 light years. The scientists estimate that the dark matter plus baryon mass associated with the object is about one billion solar masses, while its dust mass is approximately 10 million times greater than that of the sun.The images obtained by ALMA allowed the researchers to draw conclusions that the newly detected object is most likely a dusty dark dwarf galaxy, previously undetected in either optical, near-infrared or radio bands.”Our findings suggest that the object is a dusty dark dwarf galaxy,” the paper reads.However, the astronomers also explore the possibility that “object Y” could be an UDG. With stellar masses typical of dwarf galaxies, UDGs are extremely-low-density galaxies. The largest UDGs have sizes comparable to the Milky Way but contain only about one percent as many stars as our home galaxy. Notably, the phenomenon of UDGs still puzzles scientists as they try explain why these faint but large galaxies are not ripped apart by the tidal fields of their host clusters.The researchers explain that if “object Y” is a UDG, then its stellar components may have been expanded due to outflow caused by starburst or active galactic nucleus (AGN) activity. Therefore, the surface brightness in the optical and near-infrared band can be extremely small despite being gas-rich, which makes this object difficult to spot.The team concluded that more detailed analysis of the newly found object could provide important information about the origin of past starburst activity. They also noted that if “object Y” is residing in the intervening line of sight, many faint submillimeter galaxies may be classified in the future as gas-rich dusty dark dwarf galaxies.”A substantial portion of faint submillimeter galaxies (SMGs) in the universe may be attributed to such dark objects,” the researchers wrote in the paper. Citation: Mysterious faint object detected in the vicinity of a quadruply lensed quasar (2017, January 25) retrieved 18 August 2019 from https://phys.org/news/2017-01-mysterious-faint-vicinity-quadruply-lensed.html (Phys.org)—Astronomers have spotted a mysterious faint object in the vicinity of a quadruply lensed quasar designated MG 0414+0534. The object, which was discovered using the Atacama Large Millimeter/submillimeter Array (ALMA), appears to be a dusty, dark dwarf galaxy or an ultra-diffuse galaxy (UDG). The findings were presented January 19 in a paper published on arXiv.org. © 2017 Phys.org Explore further 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.last_img read more

Former Cardinals kicker Phil Dawson retires

first_img Former Cardinals kicker Phil Dawson retires Derrick Hall satisfied with D-backs’ buying and selling Arizona could be the beneficiary of the potential turnover in New England when it comes to the next coach.After interviewing with the team last Saturday, there was little information on Patriots linebackers coach Brian Flores regarding the meeting, but a recent report may indicate the coach is still very much in the running for the job. Top Stories New England Patriots safeties coach Brian Flores, right, walks on the sideline during practice Friday, Jan. 30, 2015, in Tempe, Ariz. The Patriots play the Seattle Seahawks in NFL football Super Bowl XLIX Sunday, Feb. 1. (AP Photo/Mark Humphrey) 15 Comments   Share   center_img According to reports, Flores was the fifth coach the Cardinals met with following the departure of Bruce Arians. Grace expects Greinke trade to have emotional impact The 5: Takeaways from the Coyotes’ introduction of Alex Meruelo Good chance the Patriots lose both coordinators to HC jobs, but LB coach Brian Flores is very much in play in Arizona, per league sources, meaning New England could potentially lose three assistants to HC jobs.— Adam Schefter (@AdamSchefter) January 13, 2018Flores has been with the Patriots since 2004, working all the way up from a scouting assistant at the age of 23 to the safeties coach in 2012. He spent four seasons with the safeties before turning his focus to the linebackers. The Cardinals are reportedly the only team that requested an interview with the Patriots linebackers coach the past two seasons.last_img read more