ABSTRACT
We introduce ProSpect, a generative galaxy spectral energy distribution (SED) package that encapsulates the best practices for SED methodologies in a number of astrophysical domains. ...ProSpect comes with two popular families of stellar population libraries (BC03 and EMILES), and a large variety of methods to construct star formation and metallicity histories. It models dust through the use of a Charlot & Fall attenuation model, with re-emission using Dale far-infrared templates. It also has the ability to model active galactic nucleus (AGN) through the inclusion of a simple AGN and hot torus model. Finally, it makes use of MAPPINGS-III photoionization tables to produce line emission features. We test the generative and inversion utility of ProSpect through application to the Shark galaxy formation semi-analytic code, and informed by these results produce fits to the final ultraviolet to far-infrared photometric catalogues produces by the Galaxy and Mass Assembly Survey. As part of the testing of ProSpect, we also produce a range of simple photometric stellar mass approximations covering a range of filters for both observed frame and rest-frame photometry.
ABSTRACT
We present the new ProFuse r package, a simultaneous spectral (ultraviolet to far-infrared) and spatial structural decomposition tool that produces physical models of galaxies and their ...components. This combines the functionality of the recently released ProFound (for automatic source extraction), ProFit (for extended source profiling), and ProSpect (for stellar population modelling) software packages. The key novelty of ProFuse is that it generates images using a self-consistent model for the star formation and metallicity history of the bulge and disc separately, and uses target images across a range of wavelengths to define the model likelihood and optimize our physical galaxy reconstruction. The first part of the paper explores the ProFuse approach in detail, and compares results to published structural and stellar population properties. The latter part of the paper applies ProFuse to 6664 z < 0.06 GAMA galaxies. Using re-processed ugriZYJHKs imaging we extract structural and stellar population properties for bulges and discs in parallel. As well as producing true stellar mass based mass–size relationships, we further extend this correlation to explore the third dimensions of age and gas phase metallicity. The discs in particular demonstrate strong co-dependency between mass–size–age in a well-defined plane, where at a given disc stellar mass younger discs tend to be larger. These findings are in broad agreement with work at higher redshift, suggesting discs that formed earlier are physically smaller.
ABSTRACT
The star-formation rate in galaxies is well known to correlate with stellar mass (the ‘star-forming main sequence’). Here, we extend this further to explore any additional dependence on ...galaxy surface brightness, a proxy for stellar mass surface density. We use a large sample of low-redshift (z ≤ 0.08) galaxies from the Galaxy And Mass Assembly survey which have both spectral energy distribution (SED) derived star-formation rates and photometric bulge-disc decompositions, the latter providing measures of disc surface brightness and disc masses. Using two samples, one of galaxies fitted by a single component with Sérsic index below 2 and one of the discs from two-component fits, we find that once the overall mass dependence of star-formation rate is accounted for, there is no evidence in either sample for a further dependence on stellar surface density.
ABSTRACT
Here, we present a catalogue of blended spectra in Data Release 1 of the Deep Extragalactic VIsible Legacy Survey (DEVILS) on the Anglo-Australian Telescope. Of the 23 197 spectra, 181 ...showed signs of a blend of redshifts and spectral templates. We examine these blends in detail for signs of either a candidate strong lensing galaxy or a useful overlapping galaxy pair. One of the three DEVILS target fields, COSMOS (D10), is close to complete and it is fully imaged with Hubble Space Telescope Advanced Camera for Surveys, and we visually examine the 57 blended spectra in this field in the F814W postage stamps. Nine are classical strong lensing candidates with an elliptical as the lens, out to higher redshifts than any previous search with spectroscopic surveys such as Sloan Digital Sky Survey (SDSS) or Galaxy And Mass Assembly. The gravitational lens candidate success rate is similar to earlier such searches (0.1 per cent). Strong gravitational lenses identified with blended spectroscopy have typically shown a high success rate (>70 per cent), which make these interesting targets for future higher resolution lensing studies, monitoring for supernova cosmography, or searches for magnified atomic hydrogen signal.
ABSTRACT
We present early science results from the First Large Absorption Survey in H i (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen (H i) gas at cosmological ...distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for H i absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between z = 0.34 and 0.79 over a sky area of approximately 50 deg2. In a purely blind search, we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the H i spin temperature of Tspin = 100 K and source covering fraction cf = 1, the total comoving absorption path-length sensitive to all Damped Lyman α Absorbers (DLAs; NH i ≥ 2 × 1020 cm−2) is ΔX = 6.6 ± 0.3 (Δz = 3.7 ± 0.2) and super-DLAs (NH i ≥ 2 × 1021 cm−2) is ΔX = 111 ± 6 (Δz= 63 ± 3). We estimate upper limits on the H i column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross-matching our sample of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at z = 0.3562 towards NVSS J224500−343030, with a column density of $N_{\rm H\,\small{I}} = (1.2 \pm 0.1) \times 10^{20}\, (T_{\rm spin}/100\, \mathrm{K})$ cm−2. The absorber is associated with GAMA J22450.05−343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive (MH i ≳ 3 × 109 M⊙) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe.
ABSTRACT
The Deep Extragalactic VIsible Legacy Survey (DEVILS) is an ongoing high-completeness, deep spectroscopic survey of ∼60 000 galaxies to Y < 21.2 mag, over ∼6 deg2 in three well-studied deep ...extragalactic fields: D10 (COSMOS), D02 (XMMLSS), and D03 (ECDFS). Numerous DEVILS projects all require consistent, uniformly derived and state-of-the-art photometric data with which to measure galaxy properties. Existing photometric catalogues in these regions either use varied photometric measurement techniques for different facilities/wavelengths leading to inconsistencies, older imaging data and/or rely on source detection and photometry techniques with known problems. Here, we use the ProFound image analysis package and state-of-the-art imaging data sets (including Subaru-HSC, VST-VOICE, VISTA-VIDEO, and UltraVISTA-DR4) to derive matched-source photometry in 22 bands from the FUV to 500 $\mu$m. This photometry is found to be consistent, or better, in colour analysis to previous approaches using fixed-size apertures (which are specifically tuned to derive colours), but produces superior total source photometry, essential for the derivation of stellar masses, star formation rates, star formation histories, etc. Our photometric catalogue is described in detail and, after internal DEVILS team projects, will be publicly released for use by the broader scientific community.
Context. Radio jets are present in a diverse sample of AGN. However, the mechanisms of jet powering are not fully understood, and it remains unclear to what extent they obey mass-invariant scaling ...relations similar to those found for the triggering and fuelling of X-ray-selected AGN. Aims. We use the multi-wavelength data in the eFEDS field observed by eROSITA/Spectrum-Roentgen-Gamma (SRG) and LOFAR to study the incidence of X-ray and radio AGN as a function of several stellar mass ( M * )-normalised AGN power indicators. Methods. From the LOFAR – eFEDS survey, we defined a new sample of radio AGN, with optical counterparts from Legacy Survey DR9, according to a radio-excess relative to their host star formation rate. We further divided the sample into compact and complex radio morphologies. In this work, we used the subset matching to the well-characterised, highly complete spectroscopic GAMA09 galaxies (0 < z < 0.4). We release this value-added LOFAR – eFEDS catalogue * . We calculated the fraction of GAMA09 galaxies hosting radio, X-ray, and both radio and X-ray AGN as functions of the specific black hole kinetic ( λ Jet ) and radiative ( λ Edd ) power. Results. Despite the soft-X-ray eROSITA-selected sample, the incidence of X-ray AGN as a function of λ Edd shows the same mass-invariance and power law slope (−0.65) as that found in previous studies once corrected for completeness. Across the M * range probed, the incidence of compact radio AGN as a function of λ Jet is described by a power law with constant slope, showing that it is not only high mass galaxies hosting high power jets and vice versa. This slope is steeper than that of the X-ray incidence, which has a value of around −1.5. Furthermore, higher-mass galaxies are more likely to host radio AGN across the λ Jet range, indicating some residual mass dependence of jet powering. Upon adding complex radio morphologies, including 34 FRIIs, three of which are giant radio galaxies, the incidence not only shows a larger mass dependence but also a jet power dependence, being clearly boosted at high λ Jet values. Importantly, the latter effect cannot be explained by such radio AGN residing in more dense environments (or more massive dark matter haloes). The similarity in the incidence of quiescent and star-forming radio AGN reveals that radio AGN are not only found in “red and dead” galaxies. Overall, our incidence analysis reveals some fundamental statistical properties of radio AGN samples, but highlights open questions regarding the use of a single radio luminosity–jet power conversion. We explore how different mass and accretion rate dependencies of the incidence can explain the observed results for varying disk–jet coupling models.
ProPane: image warping with fire Robotham, A S G; Tobar, R; Bellstedt, S ...
Monthly notices of the Royal Astronomical Society,
02/2024, Letnik:
528, Številka:
3
Journal Article
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ABSTRACT
In this paper, we introduce the software package propane, written for the r data analysis language. propane combines the full range of wcslib projections with the C++ image manipulation ...routines provided by the cimg library. propane offers routines for image warping and combining (including stacking), and various related tasks such as image alignment tweaking and pixel masking. It can stack an effectively unlimited number of target frames using multiple parallel cores, and offers threading for many lower level routines. It has been used for a number of current and upcoming large surveys, and we present a range of its capabilities and features. propane is already available under a permissive open-source LGPL-3 license at github.com/asgr/ProPane (DOI: 10.5281/zenodo.10057053).
ABSTRACT We present a study of kinematic asymmetries from the integral field spectroscopic surveys MAGPI and SAMI. By comparing the asymmetries in the ionized gas and stars, we aim to disentangle the ...physical processes that contribute to kinematic disturbances. We normalize deviations from circular motion by S05, allowing us to study kinematic asymmetries in the stars and gas, regardless of kinematic temperature. We find a similar distribution of stellar asymmetries in galaxies where we do and do not detect ionized gas, suggesting that whatever is driving the stellar asymmetries does not always lead to gas removal. In both MAGPI and SAMI, we find an anticorrelation between stellar asymmetry and stellar mass, that is absent in the gas asymmetries. After stellar mass and mean-stellar-age matching distributions, we find that at all stellar masses, MAGPI galaxies display larger stellar asymmetry compared to SAMI galaxies. In both MAGPI and SAMI galaxies, we find that star-forming galaxies with old mean-stellar-ages typically have larger asymmetries in their gas compared to their stars, whereas galaxies with young mean-stellar-ages have larger asymmetries in their stars compared to their gas. We suggest that this results from continuous, clumpy accretion of gas.
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