The Redshift of the Gravitationally Lensed Radio Source PKS 1830−211

Lidman, C.; Courbin, F.; Meylan, G.; Broadhurst, Tom; Frye, Brenda; Welch, William J.

doi:10.1086/311949

Cited by 79 publications

(82 citation statements)

References 22 publications

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“…These two components may arise from rapidly rotating gas near the center of the galaxy, e.g., in a circumnuclear ring. Finally, we emphasize that we were unable to identify any lines originating from the second intervening galaxy at z = 0.1926 (Lovell et al 1996), neither from the host galaxy of the quasar at z = 2.5 (Lidman et al 1999), nor from Galactic absorption.…”

Section: Additional Velocity Componentsmentioning

confidence: 70%

Molecules atz= 0.89

Müller

Beelen

Guèlin

et al. 2011

A&A

161

284

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We present the results of a 7 mm spectral survey of molecular absorption lines originating in the disk of a z = 0.89 spiral galaxy located in front of the quasar PKS 1830−211. Our survey was performed with the Australia Telescope Compact Array and covers the frequency interval 30-50 GHz, corresponding to the rest-frame frequency interval 57-94 GHz. A total of 28 different species, plus 8 isotopic variants, were detected toward the south-west absorption region, located about 2 kpc from the center of the z = 0.89 galaxy, which therefore has the largest number of detected molecular species of any extragalactic object so far. The results of our rotation diagram analysis show that the rotation temperatures are close to the cosmic microwave background temperature of 5.14 K that we expect to measure at z = 0.89, whereas the kinetic temperature is one order of magnitude higher, indicating that the gas is subthermally excited. The molecular fractional abundances are found to be in-between those in typical Galactic diffuse and translucent clouds, and clearly deviate from those observed in the dark cloud TMC 1 or in the Galactic center giant molecular cloud Sgr B2. The isotopic ratios of carbon, nitrogen, oxygen, and silicon deviate significantly from the solar values, which can be linked to the young age of the z = 0.89 galaxy and a release of nucleosynthesis products dominated by massive stars. Toward the north-east absorption region, where the extinction and column density of gas is roughly one order of magnitude lower than toward the SW absorption region, only a handful of molecules are detected. Their relative abundances are comparable to those in Galactic diffuse clouds. We also report the discovery of several new absorption components, with velocities spanning between −300 and +170 km s −1 . Finally, the line centroids of several species (e.g., CH 3 OH, NH 3 ) are found to be significantly offset from the average velocity. If caused by a variation in the proton-to-electron mass ratio μ with redshift, these offsets yield an upper limit | Δμ μ | < 4×10 −6 , which takes into account the kinematical noise produced by the velocity dispersion measured from a large number of molecular species.

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Section: Additional Velocity Componentsmentioning

confidence: 70%

Molecules atz= 0.89

Müller

Beelen

Guèlin

et al. 2011

A&A

161

284

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“…PKS 1830-211 is composed of a background continuum source at redshift z = 2.507, possibly a blazar, and a lensing face-on spiral galaxy at z = 0.88582 along its line-of-sight (Wiklind & Combes 1996b;Lidman et al 1999;Courbin et al 2002; Winn et al 2002;de Rosa et al 2005). The lens splits the background continuum into three main components, two compact hotspots, a north-western and a south-eastern one separated by ∼1 , and an Einstein ring, which is prominent at low ( 10 GHz) frequencies.…”

Section: Resultsmentioning

confidence: 99%

The density, the cosmic microwave background, and the proton-to-electron mass ratio in a cloud at redshift 0.9

Henkel¹,

Menten²,

Murphy

et al. 2009

A&A

151

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Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS 1830-211, which is by far the best known target to study dense cool gas in absorption at intermediate redshift.Determining average radial velocities and performing Large Velocity Gradient radiative transfer calculations, the aims of this study are (1) to determine the density of the gas, (2) to constrain the temperature of the cosmic microwave background (CMB), and (3) to evaluate the proton-to-electron mass ratio at redshift z ∼ 0.89. Analyzing data from six rotational HC 3 N transitions (this includes the J = 7 ← 6 line, which is likely detected for the first time in the interstellar medium) we obtain n(H 2 ) ∼ 2600 cm −3 for the gas density of the south-western absorption component, assuming a background source covering factor, which is independent of frequency. With a possibly more realistic frequency dependence proportional to ν 0.5 (the maximal exponent permitted by observational boundary conditions), n(H 2 ) ∼ 1700 cm −3 . Again toward the south-western source, excitation temperatures of molecular species with optically thin lines and higher rotational constants are, on average, consistent with the expected temperature of the cosmic microwave background, T CMB = 5.14 K. However, individually, there is a surprisingly large scatter which far surpasses expected uncertainties. A comparison of CS J = 1 ← 0 and 4 ← 3 optical depths toward the weaker north-western absorption component results in T ex = 11 K and a 1-σ error of 3 K. For the main component, a comparison of velocities determined from ten optically thin NH 3 inversion lines with those from five optically thin rotational transitions of HC 3 N, observed at similar frequencies, constrains potential variations of the proton-to-electron mass ratio μ to Δμ/μ < 1.4 × 10 −6 with 3-σ confidence. Also including optically thin rotational lines from other molecular species, it is emphasized that systematic errors are ΔV < 1 km s −1 , corresponding to Δμ/μ < 1.0 × 10 −6 .

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“…The lens is a face-on spiral galaxy at redshift z = 0.886 (Wiklind & Combes 1996, 2001Winn et al 2002). The quasi-stellar object, a blazar with a powerful jet, has redshift z = 2.507 (Lidman et al 1999).…”

Section: Pks 1830-211 As Gravitationally-lensed Systemmentioning

confidence: 99%

Resolving the High-Energy Universe With Strong Gravitational Lensing: The Case of PKS 1830–211

Barnacka

Geller

Dell’Antonio

et al. 2015

ApJ

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Gravitational lensing is a potentially powerful tool for elucidating the origin of gamma-ray emission from distant sources. Cosmic lenses magnify the emission from distance sources and produce time delays between mirage images. Gravitationally-induced time delays depend on the position of the emitting regions in the source plane. The Fermi/LAT telescope continuously monitors the entire sky and detects gamma-ray flares, including those from gravitationally-lensed blazars. Therefore, temporal resolution at gamma-ray energies can be used to measure these time delays, which, in turn, can be used to resolve the origin of the gamma-ray flares spatially. We provide a guide to the application and Monte Carlo simulation of three techniques for analyzing these unresolved light curves: the Autocorrelation Function, the Double Power Spectrum, and the Maximum Peak Method. We apply these methods to derive time delays from the gamma-ray light curve of the gravitationally-lensed blazar PKS 1830-211. The result of temporal analysis combined with the properties of the lens from radio observations yield an improvement in spatial resolution at gamma-ray energies by a factor of 10000. We analyze four active periods. For two of these periods, the emission is consistent with origination from the core and for the other two, the data suggest that the emission region is displaced from the core by more that ∼ 1.5 kpc. For the core emission, the gamma-ray time delays, 23 ± 0.5 days and 19.7 ± 1.2 days, are consistent with the radio time delay 26 +4 −5 days.

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The Redshift of the Gravitationally Lensed Radio Source PKS 1830−211

Cited by 79 publications

References 22 publications

Molecules atz= 0.89

Molecules atz= 0.89

The density, the cosmic microwave background, and the proton-to-electron mass ratio in a cloud at redshift 0.9

Resolving the High-Energy Universe With Strong Gravitational Lensing: The Case of PKS 1830–211

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