AutoSpec: Fast Automated Spectral Extraction Software for IFU Data Cubes

Griffiths, Alex; Conselice, Christopher J.

doi:10.3847/1538-4357/aaee87

Cited by 3 publications

(3 citation statements)

References 15 publications

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“…We outlined an observing strategy that JWST may use to observe these objects. To minimize the effects from microlensing in the modeling of caustic transits, one could also target some compact galaxy clusters at 0.3 z 0.5 that have a smaller fraction of ICL compared to their total galaxy light at the z 7 lensing contours, but that -due to their compactness -have excellent lensing properties (e.g., Griffiths et al 2018).…”

Section: Possible Observing Programs Tomentioning

confidence: 99%

On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits

Windhorst

Alpaslan

Andrews

et al. 2018

ApJS

101

112

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Recent near-infrared power-spectra and panchromatic Extragalactic Background Light (EBL) measurements provide upper limits on the integrated near-infrared surface brightness (SB > ∼ 31mag arcsec −2 at 2µm) that may come from Population III (Pop III) stars and possible accretion disks around resulting stellar-mass black holes (BHs) in the epoch of First Light, broadly taken from z 7-17. Physical parameters for zero metallicity Pop III stars at z > ∼ 7 can be estimated from MESA stellar evolution models through helium-depletion, and for BH accretion disks from quasar microlensing results and multicolor accretion models. Second-generation non-zero metallicity stars can form at higher multiplicity, so that BH accretion disks may be fed by Roche-lobe overflow from lower-mass companions in their AGB stage. The near-infrared SB constraints can be used to calculate the number of caustic transits behind lensing clusters that the James Webb Space Telescope (JWST) and the next generation 25-39 m ground-based telescopes may detect for both Pop III stars and stellar mass BH accretion disks. Because Pop III stars and stellar mass BH accretion disks have sizes of a few×10 −11 arcsec at z > ∼ 7, typical caustic magnifications can be µ 10 4 -10 5 , with rise times of hours and decline times of < ∼ 1 year for cluster transverse velocities of v T < ∼ 1000 km s −1 . Microlensing by intracluster medium objects can modify transit magnifications, and lengthen visibility times. Depending on BH masses, accretion-disk radii and feeding efficiencies, stellar-mass BH accretion-disk caustic transits could outnumber those from Pop III stars. To observe Pop III caustic transits directly may require monitoring 3-30 lensing clusters to AB < ∼ 29 mag over a decade or more. Such a program must be started with JWST at the start of Cycle 1, and -depending on the role of microlensing in the Intra Cluster Light (ICL) -should be continued for decades with the next generation 25-39 m ground-based telescopes, where both JWST and the ground-based facilities each will play a unique and strongly complementary role.

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Section: Possible Observing Programs Tomentioning

confidence: 99%

On the Observability of Individual Population III Stars and Their Stellar-mass Black Hole Accretion Disks through Cluster Caustic Transits

Windhorst

Alpaslan

Andrews

et al. 2018

ApJS

101

112

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“…Formally, a reference image of the same resolution as the data cube itself, like for instance a white light image, can also be used as the starting point for spectral extractions with TDOSE, if ancillary data is unavailable. The use of ancillary (higher-resolution) reference images was deliberately avoided in the spectral extraction tool AUTOSPEC (Griffiths & Conselice 2018) to make the method self-contained. However, providing a higher-resolution reference image allows for de-blending of sources which are unresolved at the IFS PSF resolution, which is one of the main strengths of the approach taken by TDOSE.…”

Section: Determining Sources In Reference Imagementioning

confidence: 99%

“…accounting for the flux contribution of all objects to all pixels in the FoV, a spectral extraction accounting for the morphology of individual objects and the wavelength dependent point spread function (PSF) optimizing the signal-to-noise ratio (S/N) of the spectra, is needed. Tools for extracting pointsources, e.g., stars (PampelMuse; Kamann et al 2013) and extended objects, e.g., (AUTOSPEC; Griffiths & Conselice 2018) have been developed with this in mind. Such spectral extractions where the source morphology is accounted for, are often referred to as "optimal" spectral extractions.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Optimal Spectral Extraction (TDOSE) from integral field spectroscopy

Schmidt

Wisotzki

Urrutia

et al. 2019

A&A

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The amount of integral field spectrograph (IFS) data has grown considerable over the last few decades. The demand for tools to analyze such data is therefore bigger now than ever. We present TDOSE; a flexible Python tool for Three Dimensional Optimal Spectral Extraction from IFS data cubes. TDOSE works on any three-dimensional data cube and bases the spectral extractions on morphological reference image models. By default, these models are generated and composed of multiple multivariate Gaussian components, but can also be constructed with independent modeling tools and be provided as input to TDOSE. In each wavelength layer of the IFS data cube, TDOSE simultaneously optimizes all sources in the morphological model to minimize the difference between the scaled model components and the IFS data. The flux optimization produces individual data cubes containing the scaled three-dimensional source models. This allows for efficient de-blending of flux in both the spatial and spectral dimensions of the IFS data cubes, and extraction of the corresponding one-dimensional spectra. TDOSE implicitly requires an assumption about the twodimensional light distribution. We describe how the flexibility of TDOSE can be used to mitigate and correct for deviations from the input distribution. Furthermore, we present an example of how the three-dimensional source models generated by TDOSE can be used to improve two-dimensional maps of physical parameters like velocity, metallicity or SFR, when flux contamination is a problem. By extracting TDOSE spectra of ∼150 [OII] emitters from the MUSE-Wide survey we show that the median increase in line flux is ∼5% when using multi-component models as opposed to single-component models. However, the increase in recovered line emission in individual cases can be as much as 50%. Comparing the TDOSE model-based extractions of the MUSE-Wide [OII] emitters with aperture spectra, the TDOSE spectra provides a median flux (S/N) increase of 9% (14%). Hence, TDOSE spectra optimizes the S/N while still being able to recover the total emitted flux. TDOSE version 3.0 presented in this paper is available at https://github.com/kasperschmidt/TDOSE and Schmidt (2019).

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