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Tool reference. 75% of classified Pith citations use this work as a method, library, or software dependency, not as a substantive claim.

22 Pith papers citing it
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Method reference 75% of classified citations
abstract

I start by providing an updated summary of the penalized pixel-fitting (pPXF) method, which is used to extract the stellar and gas kinematics, as well as the stellar population of galaxies, via full spectrum fitting. I then focus on the problem of extracting the kinematic when the velocity dispersion $\sigma$ is smaller than the velocity sampling $\Delta V$, which is generally, by design, close to the instrumental dispersion $\sigma_{\rm inst}$. The standard approach consists of convolving templates with a discretized kernel, while fitting for its parameters. This is obviously very inaccurate when $\sigma<\Delta V/2$, due to undersampling. Oversampling can prevent this, but it has drawbacks. Here I present a more accurate and efficient alternative. It avoids the evaluation of the under-sampled kernel, and instead directly computes its well-sampled analytic Fourier transform, for use with the convolution theorem. A simple analytic transform exists when the kernel is described by the popular Gauss-Hermite parametrization (which includes the Gaussian as special case) for the line-of-sight velocity distribution. I describe how this idea was implemented in a significant upgrade to the publicly available pPXF software. The key advantage of the new approach is that it provides accurate velocities regardless of $\sigma$. This is important e.g. for spectroscopic surveys targeting galaxies with $\sigma\ll\sigma_{\rm inst}$, for galaxy redshift determinations, or for measuring line-of-sight velocities of individual stars. The proposed method could also be used to fix Gaussian convolution algorithms used in today's popular software packages.

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2026 20 2025 2

representative citing papers

Tidal pre-conditioning and ram-pressure stripping in NGC 1427A. Deep VLT/MUSE spectroscopy and FUV-to-radio observations trace a Fornax Cluster dwarf in transformation

astro-ph.GA · 2026-05-01 · unverdicted · novelty 6.0 · 2 refs

Multi-phase observations of NGC 1427A indicate tidal torquing from a dwarf fly-by has pre-conditioned its gas for ram-pressure stripping by the Fornax intracluster medium, placing the galaxy at the onset of environmental quenching with a declining star formation rate.

Radial Profiles of Binary Fraction in Elliptical Galaxies

astro-ph.GA · 2026-04-29 · unverdicted · novelty 5.0

Binary fractions in elliptical galaxies remain approximately flat with radius once stellar population variations are subtracted, showing less than 5% change at one effective radius for nearly all galaxies studied.

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Showing 22 of 22 citing papers.