Vasan G. C., Keerthi;
Jones, Tucker;
Sanders, Ryan L;
Ellis, Richard S;
Stark, Daniel P;
Kacprzak, Glenn G;
Barone, Tania M;
... Jacobs, Colin; + view all
(2023)
Resolved Velocity Profiles of Galactic Winds at Cosmic Noon.
The Astrophysical Journal
, 959
(2)
, Article 124. 10.3847/1538-4357/acf462.
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Abstract
We study the kinematics of the interstellar medium (ISM) viewed “down the barrel” in 20 gravitationally lensed galaxies during cosmic noon (z = 1.5–3.5). We use moderate-resolution spectra (R ∼ 4000) from Keck’s Echellette Spectrograph and Imager and Magellan/MagE to spectrally resolve the ISM absorption in these galaxies into ∼10 independent elements and use double Gaussian fits to quantify the velocity structure of the gas. We find that the bulk motion of gas in this galaxy sample is outflowing, with average velocity centroid <?CDATA $\left\langle {v}_{\mathrm{cent}}\right\rangle =-141$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mfenced close="〉" open="〈"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>v</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>cent</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:mfenced> <mml:mo>=</mml:mo> <mml:mo>−</mml:mo> <mml:mn>141</mml:mn> </mml:math> km s−1 (±111 km s−1 scatter) measured with respect to the systemic redshift. A total of 16 out of the 20 galaxies exhibit a clear positive skewness, with a blueshifted tail extending to ∼ −500 km s−1. We examine scaling relations in outflow velocities with galaxy stellar mass and star formation rate, finding correlations consistent with a momentum-driven wind scenario. Our measured outflow velocities are also comparable to those reported for FIRE-2 and TNG50 cosmological simulations at similar redshift and galaxy properties. We also consider implications for interpreting results from lower-resolution spectra. We demonstrate that while velocity centroids are accurately recovered, the skewness, velocity width, and probes of high-velocity gas (e.g., v 95) are subject to large scatter and biases at lower resolution. We find that R ≳ 1700 is required for accurate results for the gas kinematics of our sample. This work represents the largest available sample of well-resolved outflow velocity structure at z > 2 and highlights the need for good spectral resolution to recover accurate properties.
| Type: | Article |
|---|---|
| Title: | Resolved Velocity Profiles of Galactic Winds at Cosmic Noon |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/acf462 |
| Publisher version: | http://dx.doi.org/10.3847/1538-4357/acf462 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10184843 |
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