On modeling galaxy-scale strong lens systems

Keeton, Charles R.

doi:10.1007/s10714-010-1041-1

Cited by 52 publications

(36 citation statements)

References 87 publications

(148 reference statements)

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“…We took advantage of a dusty spiral galaxy, CLASH 2882 [37][38][39] , in our ALMA field-of-view to examine possible astrometric off- As can be seen from the HST morphology shown on Figure 1 Magnification factor. With our new spectroscopic redshift, we revisited the magnification calculations using all the mass models released in the framework of the Frontier Fields survey [40][41][42][43][44][45][46] 7 . In addition, we use our deep upper limit on dust continuum emission as well as our measurement of the [OIII] flux described above.…”

Section: -0198 Japanmentioning

confidence: 99%

The onset of star formation 250 million years after the Big Bang

Hashimoto¹,

Laporte²,

Mawatari³

et al. 2018

Nature

374

416

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A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang. The abundance of star-forming galaxies is known to decline from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD1 , a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.

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Section: -0198 Japanmentioning

confidence: 99%

The onset of star formation 250 million years after the Big Bang

Hashimoto¹,

Laporte²,

Mawatari³

et al. 2018

Nature

374

416

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“…When fitting the SIE, we vary the Einstein radius, position, ellipticity, shear, and the two corresponding position angles. We optimize these parameters simultaneously, first optimizing numerous random realizations of an SIE profile in the source plane, and then keeping and re-optimizing the best model in the image plane (see Keeton 2010).…”

Section: Fitting Proceduresmentioning

confidence: 99%

Strong lensing signatures of luminous structure and substructure in early-type galaxies

Gilman

Agnello

Treu

et al. 2017

Mon. Not. R. Astron. Soc.

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The arrival times, positions, and fluxes of multiple images in strong lens systems can be used to infer the presence of dark subhalos in the deflector, and thus test predictions of cold dark matter models. However, gravitational lensing does not distinguish between perturbations to a smooth gravitational potential arising from baryonic and non-baryonic mass. In this work, we quantify the extent to which the stellar mass distribution of a deflector can reproduce flux ratio and astrometric anomalies typically associated with the presence of a dark matter subhalo. Using Hubble Space Telescope images of nearby galaxies, we simulate strong lens systems with real distributions of stellar mass as they would be observed at redshift z d = 0.5. We add a dark matter halo and external shear to account for the smooth dark matter field, omitting dark substructure, and use a Monte Carlo procedure to characterize the distributions of image positions, time delays, and flux ratios for a compact background source of diameter 5 pc. By convolving high-resolution images of real galaxies with a Gaussian PSF, we simulate the most detailed smooth potential one could construct given high quality data, and find scatter in flux ratios of ≈ 10%, which we interpret as a typical deviation from a smooth potential caused by large and small scale structure in the lensing galaxy. We demonstrate that the flux ratio anomalies arising from galaxyscale baryonic structure can be minimized by selecting the most massive and round deflectors, and by simultaneously modeling flux ratio and astrometric data.

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“…We may consider the astrometry in Table 1 of Sergeyev et al (2016) and the lens magnification ratio we derive in Section 4, i.e., a macrolens flux ratio B/A = 0.64 ± 0.064, where the uncertainty is increased to 10% to take an unknown microlens effect into account. If we fit a singular isothermal ellipsoid (SIE) mass model to these observations (χ 2 ∼ 0), the LENSMODEL software (Keeton 2001(Keeton , 2010 produces an Einstein radius, ellipticity (position angle), and time delay of 1. 073, 0.034 (−28.…”

Section: Discussionmentioning

confidence: 99%

Gravitationally Lensed Quasar SDSS J1442+4055: Redshifts of Lensing Galaxies, Time Delay, Microlensing Variability, and Intervening Metal System at z ∼ 2

Shalyapin

Goicoechea

2019

ApJ

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We present an r-band photometric monitoring of the two images A and B of the gravitationally lensed quasar SDSS J1442+4055 using the Liverpool Telescope (LT). From the LT light curves between 2015 December and 2018 August, we derive at once a time delay of 25.0 ± 1.5 days (1σ confidence interval; A is leading) and microlensing magnification gradients below 10 −4 mag day −1 . The delay interval is not expected to be affected by an appreciable microlensing-induced bias, so it can be used to estimate cosmological parameters. This paper also focuses on new Gran Telescopio Canarias (GTC) and LT spectroscopic observations of the lens system. We determine the redshift of two bright galaxies around the doubly imaged quasar using LT spectroscopy, while GTC data lead to low-noise individual spectra of A, B, and the main lensing galaxy G1. The G1 spectral shape is accurately matched to an earlytype galaxy template at z = 0.284, and it has potential for further relevant studies. Additionally, the quasar spectra show absorption by metal-rich gas at z ∼ 2. This dusty absorber is responsible for an extinction bump at a rest-frame wavelength of 2209 ± 2Å, which has strengths of ∼ 0.47 and 0.76 mag µm −1 for A and B, respectively. In such intervening system, the dust-to-gas ratio, gas-phase metallicity indicator [Zn/H], and dust depletion level [Fe/Zn] are relatively high.

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On modeling galaxy-scale strong lens systems

Cited by 52 publications

References 87 publications

The onset of star formation 250 million years after the Big Bang

The onset of star formation 250 million years after the Big Bang

Strong lensing signatures of luminous structure and substructure in early-type galaxies

Gravitationally Lensed Quasar SDSS J1442+4055: Redshifts of Lensing Galaxies, Time Delay, Microlensing Variability, and Intervening Metal System at z ∼ 2

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