Discovery of OH Absorption from a Galaxy at z ∼ 0.05: Implications for Large Surveys with SKA Pathfinders

Gupta, N.; Momjian, Emmanuel; Srianand, R.; Petitjean, P.; Noterdaeme, P.; Gyanchandani, D.; Sharma, Rohit; Kulkarni, S.

doi:10.3847/2041-8213/aac9cd

Cited by 23 publications

(55 citation statements)

References 46 publications

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“…For µ, a compilation of 16 recent measurements can be found in Table 2 of [6]. As for the measurements of products of α, µ and g p , Table 3 of [6] lists the 29 measurements then available, and more recently two stringent ones have been published in [36,37]. All of these will constitute our astrophysical measurements dataset.…”

Section: Current Local and Spectroscopic Measurementsmentioning

confidence: 99%

Consistency of local and astrophysical tests of the stability of fundamental constants

Martins

Miñana

2019

Physics of the Dark Universe

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Tests of the stability of nature's fundamental constants are one of the cornerstones of the ongoing search for the new physics which is required to explain the recent acceleration of the universe. The two main settings for these tests are high-resolution spectroscopy of astrophysical systems (mainly in low-density absorption clouds along the line of sight of bright quasars) and laboratory comparisons of pairs of atomic clocks. Here we use standard chisquare techniques to perform a global analysis of all currently available data, studying both the consistency of tests of stability of different constants (specifically the fine-structure constant α, the proton-to-electron mass ratio µ and the proton gyromagnetic ratio g p ) and the consistency between local laboratory and astrophysical tests. We start by doing a model-independent analysis (studying the internal consistency of the various available datasets) but also explore specific phenomenological models motivated by string theory and grand unification. Overall there is weak (one to two sigma) evidence of variations, at the level of up to a few parts per million, and reasonable agreement between laboratory and astrophysical tests. This result holds even if one removes from the analysis the Webb et al. archival dataset of α measurements. Forthcoming astrophysical facilities, such as the ESPRESSO spectrograph, should be able to confirm or rule out these hints.

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Section: Current Local and Spectroscopic Measurementsmentioning

confidence: 99%

Consistency of local and astrophysical tests of the stability of fundamental constants

Martins

Miñana

2019

Physics of the Dark Universe

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“…Indeed, G1 is a LINER and G2 a Seyfert 2, and based on their optical emission line excitation both are located in the AGN region of the Baldwin-Phillips-Terlevich (BPT) diagram (Baldwin et al 1981), plotting [OIII]/Hβ as a function of [NII]/Hα. We note that the above FIR luminosity is extrapolated between 1 and 500µm, as in Table 1, while Gupta et al (2018a) adopt the calibration formula from Article number, page 1 of 6 arXiv:1901.04683v2 [astro-ph.GA] 28 Feb 2019 Sanders & Mirabel (1996) and find L FIR = 3.5×10 11 L , which is in good agreement. The background quasar Q0248 is a wellstudied radio source and has a variable, flat spectrum (Massaro et al 2014).…”

Section: Apparent Quasar-galaxy Merger Associationmentioning

confidence: 99%

“…CO(1-0) emission spectrum toward the GO248 galaxy center. The zero of the velocity scale (z = 0.05151) is centered at the peak of the low resolution H I 21cm absorption line (Gupta et al 2018a). The systemic velocity of the two merging galaxies G1 and G2 are indicated.…”

Section: H I Absorptionmentioning

confidence: 99%

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Discovery of CO absorption at z = 0.05 in G0248+430

Combes

Gupta

Józsa

et al. 2019

A&A

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Absorption lines in front of distant quasars are quite rare in the millimeter domain. They can, however, bring very useful and complementary information to emission lines. We report here the detection with NOEMA of CO(1-0) and CN(1-0) lines in absorption, and the confirmation of CO emission in the quasar/galaxy pair Q0248+430/G0248+430. The system G0248+430 corresponds to two merging galaxies (a Seyfert and a LINER) at z=0.0519 with a tidal tail just on the line of sight to the background quasar Q0248+430 at z = 1.313. Optical (CaII, NaI), H I-21cm, and OH-1667 MHz absorption lines associated with the tidal tail of the foreground system have previously been detected toward the quasar, while four CO lines at different rotation J levels have been detected in emission from the foreground galaxies. New H I 21cm line observations with the upgraded GMRT array are also presented. We discuss the molecular content of the merging galaxies, and the physical conditions in the absorbing interstellar medium of the tidal tail.

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“…In addition, the H i 21-cm and OH 18-cm absorption lines, if detected at high significance level, can be used to place tight constraints on the variations of fundamental constants of physics (Uzan 2003). However, only six OH absorbers at cosmologically significant redshifts in radio wavelengths are known to date (Chengalur et al 1999;Chengalur & Kanekar 2003;Kanekar & Chengalur 2002;Kanekar et al 2005;Gupta et al 2018).…”

Section: Introductionmentioning

confidence: 99%

uGMRT search for cold gas at z ∼ 1–1.4 towards red quasars

Dutta

Raghunathan

Gupta

et al. 2019

Monthly Notices of the Royal Astronomical Society

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We present results from our search for H i 21-cm and OH 18-cm absorption at z ∼ 1 − 1.4 towards red quasars showing strong Mg ii absorption using uGMRT. The quasars J1501+1822 and J1521+5508 show multiple strong associated Mg ii absorption at z ∼ 1.1 and signature of reddening in their optical spectra. We report the detection of H i 21-cm absorption towards J1521+5508 at the systemic redshift of the quasar, with N (H i) = (1.2 ± 0.2) × 10 20 cm −2 for spin temperature of 100 K and unit covering factor. The H i 21-cm absorption is offset from the blueshifted strong Mg ii absorbers by 1500 km s −1 . We do not detect H i 21-cm absorption at the redshift of the associated Mg ii absorption and at the systemic redshift towards J1501+1822. We argue that lack of one-to-one correspondence between Mg ii and H i 21-cm absorption could be related with clumpiness of the neutral gas and the radio and optical sightlines probing different volume of the gas. We find that the presence of strong associated Mg ii absorption and reddening in the optical spectra of the quasars lead to an increased detection rate of associated H i 21-cm absorption at z 1. We also report non-detection of intervening OH absorption ([OH]/[H i] (1-4)×10 −8 ) at z = 1.3 towards two red quasars, J0850+5159 and J0852+3435, which show strong metal and H i 21-cm absorption and the 2175Å dust extinction bump.

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Discovery of OH Absorption from a Galaxy at z ∼ 0.05: Implications for Large Surveys with SKA Pathfinders

Cited by 23 publications

References 46 publications

Consistency of local and astrophysical tests of the stability of fundamental constants

Consistency of local and astrophysical tests of the stability of fundamental constants

Discovery of CO absorption at z = 0.05 in G0248+430

uGMRT search for cold gas at z ∼ 1–1.4 towards red quasars

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