* Astronomy

Members Login
Post Info
TOPIC: MG J0414+0534


L

Posts: 131433
Date:
RE: MG J0414+0534
Permalink  
 


Title: Detection of Substructure in the Gravitationally Lensed Quasar MG0414+0534 using Mid-Infrared and Radio VLBI Observations
Authors: Chelsea L MacLeod, Ramsey Jones, Eric Agol, Christopher S. Kochanek

We present 11.2 micron observations of the gravitationally lensed, radio-loud z_s=2.64 quasar MG0414+0534, obtained using the Michelle camera on Gemini North. We find a flux ratio anomaly of A2/A1= 0.93 ±0.02 for the quasar images A1 and A2. When combined with the 11.7 micron measurements from Minezaki et al.\ (2009), the A2/A1 flux ratio is nearly 5-sigma from the expected ratio for a model based on the two visible lens galaxies. The mid-IR flux ratio anomaly can be explained by a satellite (substructure), 0.3" Northeast of image A2, as can the detailed VLBI structures of the jet produced by the quasar. When we combine the mid-IR flux ratios with high-resolution VLBI measurements, we find a best-fit mass of 10^(7.3 ±0.2) solar masses inside the Einstein radius for a satellite substructure modelled as a singular isothermal sphere at the redshift of the main lens (z_l=0.96). We are unable to set an interesting limit on the mass to light ratio due to its proximity to the quasar image A2. While the observations used here were technically difficult, surveys of flux anomalies in gravitational lenses with the James Webb Space Telescope will be simple, fast, and should well constrain the abundance of substructure in dark matter haloes.

Read more (178kb, PDF)



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: Long term Arecibo monitoring of the water megamaser in MG J0414+0534
Authors: P. Castangia (1), M. C. V. Impellizzeri (2), J. P. McKean (3), C. Henkel (4), A. Brunthaler (4), A. L. Roy (4), O. Wucknitz (5) ((1) INAF-Osservatorio Astronomico di Cagliari, Capoterra, Italy (2) ALMA, Chile (3) ASTRON, Dwingeloo, the Netherlands (4) Max-Planck-Institut fuer Radioastronomie, Bonn, Germany (5) Argelander-Institut fuer Astronomie, Bonn, Germany)

We monitored the 22 GHz maser line in the lensed quasar MG J0414+0534 at z=2.64 with the 300-m Arecibo telescope for almost two years to detect possible additional maser components and to measure a potential velocity drift of the lines. The main maser line profile is complex and can be resolved into a number of broad features with line widths of 30-160 km/s. A new maser component was tentatively detected in October 2008 at a velocity of +470 km/s. After correcting for the estimated lens magnification, we find that the H2O isotropic luminosity of the maser in MG J0414+0534 is about 26,000 solar luminosities, making this source the most luminous ever discovered. Both the main line peak and continuum flux densities are surprisingly stable throughout the period of the observations. An upper limit on the velocity drift of the main peak of the line has been estimated from our observations and is of the order of 2 km/s per year. We discuss the results of the monitoring in terms of the possible nature of the maser emission, associated with an accretion disk or a radio jet. This is the first time that such a study is performed in a water maser source at high redshift, potentially allowing us to study the parsec-scale environment around a powerful radio source at cosmological distances.

Read more (225kb, PDF)



__________________


L

Posts: 131433
Date:
Permalink  
 

Astronomers have found the most distant evidence of water in the Universe, a major conference has been told.
The vapour is thought to be present in a jet ejected from a supermassive black hole at the centre of a galaxy that is billions of light-years away.


Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Astronomers have found the most distant signs of water in the Universe to date. Dr John McKean of the Netherlands Institute for Radio Astronomy (ASTRON) will be presenting the discovery at the European Week of Astronomy and Space Science in Hatfield on Wednesday 22nd April.
The water vapour is thought to be contained in a jet ejected from a supermassive black hole at the centre of a galaxy, named MG J0414+0534.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Astronomers recently used the NSF's Very Large Array (VLA) radio telescope  to help find the most distant water yet seen in the Universe, in a galaxy more than 11 billion light-years from Earth. Previously, the most distant water had been seen in a galaxy less than 7 billion light-years from Earth.
The soggy galaxy is dubbed MG J0414+0534. In a region near its core, water molecules are acting as masers, the radio equivalent of lasers, to amplify radio waves at a specific frequency.
The water molecules showed themselves with a tell-tale radio "fingerprint." The first indication came from the giant, 100-meter-diameter radio telescope in Effelsberg, Germany, and scientists confirmed the discovery using the VLA. The astronomers say their finding indicates that such giant, water masers were more common in the early Universe than they are today. MG J0414+0534 is seen as it was when the Universe was roughly one-sixth of its current age.

Read more 

__________________


L

Posts: 131433
Date:
Permalink  
 

Astronomers at Max Planck Institute (MPI) for Radio Astronomy in Bonn, Germany, have spotted a mega maser emission inside a galaxy at the edge of the visible cosmos, which is the telltale sign of the presence of water.
According to a report in New Scientist, the telltale sign of the water is maser emission - the microwave equivalent of laser light - coming from warm water vapour inside a distant quasar.
The quasar, called MG J0414+0534, is so distant that its light has travelled for 11.1 billion years to reach the Earth, having left when the universe was only 2.5 billion years old.


Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Astronomers have reported finding the most distant water ever detected, in a galaxy 11 billion light-years from Earth.
Until now, the farthest water ever seen was glimpsed about 7 billion light-years from Earth. The new discovery suggests that water was common in galaxies in the early universe, which we can see when we look at objects so distant that their light has taken billions of years to reach us.


Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

Uma equipe de astrônomos alemães da cidade de Bonn detectou a presença de água à maior distância da Terra registrada até o momento, cerca de 11,1 bilhões de anos-luz.
Um porta-voz do Instituto Max Planck de Radioastronomia de Bonn especificou hoje que as partículas de água foram localizadas no quasar (corpo cósmico que emite grandes ondas de radiação) MG-J0414+0534, uma galáxia ativa muito distante de nosso planeta.

Read more

__________________


L

Posts: 131433
Date:
Permalink  
 

A research group led by graduate student Violette Impellizzeri from the Max Planck Institute for Radio Astronomy has used the 100 m Effelsberg radio telescope to detect water at the greatest distance from Earth so far. The water vapour was discovered in the quasar MG J0414+0534 at redshift 2.64, which corresponds to a light travel time of 11.1 billion years, a time when the Universe was only a fifth of the age it is today. The water vapour is thought to exist in clouds of dust and gas that feed the supermassive black hole at the centre of the distant quasar. The detection was later confirmed by high-resolution interferometric observations with the Expanded Very Large Array. The results of this work appear in the recent issue of Nature (18 December 2008).
This discovery of water in the early Universe was possible only due to the chance alignment of a foreground galaxy and the distant quasar MG J0414+0534. The foreground galaxy acts like a cosmic telescope, magnifying and distorting the light from the quasar, and forms four distinct images of the quasar. Without this gravitational lensing effect, 580 days of continuous observations with the 100 m telescope would have been needed instead of the 14 hours used to make this remarkable discovery.

"Others have tried and failed to find water, and we knew we were looking for a very faint signal, so we thought of using a foreground galaxy like a cosmic magnifying glass to observe at a far greater distance and had to be persistent, and sure enough the line emission of water popped up" - Violette Impellizzeri.

The detection of water from MG J0414+0534 with the Effelsberg radio telescope also occurred thanks to a touch of fortune. The object is within just the right redshift interval to stretch the line emission of the H2O molecule from its original frequency of 22 GHz to 6 GHz and so within the tuning range of the 6 GHz receiver installed at the telescope.

Source


Title: H i and OH absorption in the lensing galaxy of MG J0414+0534
Authors: Curran, S. J.; Darling, J.; Bolatto, A. D.; Whiting, M. T.; Bignell, C.; Webb, J. K.

We report the detection of H i21-cm absorption in the z= 0.96 early-type lensing galaxy towards MG J0414+0534 with the Green Bank Telescope. The absorption, with total NHi= 1.6 x 10^18 (Ts/f) cm^-2, is resolved into two strong components, probably due to the two strongest lens components, which are separated by 0.4 arcsec. Unlike the other three lenses that have been detected in Hi, J0414+0534 does not exhibit strong OH absorption, giving an OH/Hi column density ratio of NOH/NHi<= 10-6 (for Ts= 100 K, Tx= 10 K and fHi=fOH= 1). This underabundance of molecular gas may indicate that the extreme optical-near-infrared colour (V-K= 10.26) along the line of sight is not due to the lens. We therefore suggest that despite the strong upper limits on molecular absorption at the quasar redshift, as traced by millimetre lines, the extinction occurs primarily in the quasar host galaxy.

Source


Water has been spotted inside a galaxy at the edge of the visible cosmos. Finding other such signals could help pin down the properties of monster black holes in the early universe.
The telltale sign of the water is maser emission - the microwave equivalent of laser light - coming from warm water vapour inside a distant quasar, an energetic galaxy powered by gas and dust swirling onto a giant black hole.
The quasar, called MG J0414+0534, is so distant that its light has travelled for 11.1 billion years to reach the Earth, having left when the universe was only 2.5 billion years old. It beats the previous distance record for a watery galaxy by many billions of light years.

Read more

__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard