Dr HELEN RUSSELL's Outputs (25)

Velocity Structure Correlations between the Nebular, Molecular, and Atmospheric Gases in the Cores of Four Cool Core Clusters (2025)
Journal Article
Li, M., Mcnamara, B., Coil, A. L., Gingras, M.-J., Brighenti, F., Russell, H., Tamhaneh, P. D., Peng Oh, S., & Perrotta, S. (2025). Velocity Structure Correlations between the Nebular, Molecular, and Atmospheric Gases in the Cores of Four Cool Core Clusters. Astrophysical Journal, 984(1), Article 22. https://doi.org/10.3847/1538-4357/adc102

We investigate the velocity structure of nebular gas in the central galaxies of four clusters: Abell 1835, PKS 0745-191, Abell 262, and RXJ0820.9+0752, using data from the Keck Cosmic Web Imager (KCWI). Velocity structure functions (VSFs) of the [OII... Read More about Velocity Structure Correlations between the Nebular, Molecular, and Atmospheric Gases in the Cores of Four Cool Core Clusters.

Directly imaging the cooling flow in the Phoenix cluster (2025)
Journal Article
Reefe, M., McDonald, M., Chatzikos, M., Seebeck, J., Mushotzky, R., Veilleux, S., Allen, S. W., Bayliss, M., Calzadilla, M., Canning, R., Floyd, B., Gaspari, M., Hlavacek-Larrondo, J., McNamara, B., Russell, H., Sharon, K., & Somboonpanyakul, T. (2025). Directly imaging the cooling flow in the Phoenix cluster. Nature, 638, 360-364. https://doi.org/10.1038/s41586-024-08369-x

In the centres of many galaxy clusters, the hot (approximately 107 kelvin) intracluster medium can become dense enough that it should cool on short timescales. However, the low measured star formation rates in massive central galaxies and the absence... Read More about Directly imaging the cooling flow in the Phoenix cluster.

Complex Kinematics of Nebular Gas in Active Galaxies Centered in Cooling X-Ray Atmospheres (2024)
Journal Article
Gingras, M.-J., Coil, A. L., McNamara, B. R., Perrotta, S., Brighenti, F., Russell, H. R., Li, M., Oh, S. P., & Ning, W. (2024). Complex Kinematics of Nebular Gas in Active Galaxies Centered in Cooling X-Ray Atmospheres. The Astrophysical Journal, 977(2), Article 159. https://doi.org/10.3847/1538-4357/ad822a

[O ii] emission maps obtained with the Keck Cosmic Web Imager are presented for four galaxies centered in cooling X-ray cluster atmospheres. Nebular emission extending over tens of kiloparsecs is found in systems covering a broad range of atmospheric... Read More about Complex Kinematics of Nebular Gas in Active Galaxies Centered in Cooling X-Ray Atmospheres.

Hidden cooling flows − IV. More details on Centaurus and the efficiency of AGN feedback in clusters (2024)
Journal Article
Fabian, A. C., Ferland, G. J., Sanders, J. S., Russell, H. R., McNamara, B. R., Pinto, C., Hlavacek-Larrondo, J., Walker, S. A., Ivey, L. R., & McDonald, M. (2024). Hidden cooling flows − IV. More details on Centaurus and the efficiency of AGN feedback in clusters. Monthly Notices of the Royal Astronomical Society, 535(3), 2173–2188. https://doi.org/10.1093/mnras/stae2414

Cooling flows are common in galaxy clusters which have cool cores. The soft X-ray emission below 1 keV from the flows is mostly absorbed by cold dusty gas within the central cooling sites. Further evidence for this process is presented here through a... Read More about Hidden cooling flows − IV. More details on Centaurus and the efficiency of AGN feedback in clusters.

Complex Velocity Structure of Nebular Gas in Active Galaxies Centred in Cooling X-ray Atmospheres (2024)
Journal Article
Gingras, M.-J., Coil, A. L., Mcnamara, B. R., Perrotta, S., Brighenti, F., Russell, H. R., Li, M., Peng Oh, S., & Wenmeng, W. (in press). Complex Velocity Structure of Nebular Gas in Active Galaxies Centred in Cooling X-ray Atmospheres. Astrophysical Journal,

[OII] emission maps obtained with the Keck Cosmic Web Imager (KCWI) are presented for four galaxies centered in cooling X-ray cluster atmospheres. Nebular emission extending tens of kpc is found in systems covering a broad range of atmospheric coolin... Read More about Complex Velocity Structure of Nebular Gas in Active Galaxies Centred in Cooling X-ray Atmospheres.

Two distinct molecular cloud populations detected in massive galaxies (2024)
Journal Article
Rose, T., McNamara, B. R., Combes, F., Edge, A. C., McDonald, M., O’Sullivan, E., Russell, H., Fabian, A. C., Ferland, G., Salomé, P., & Tremblay, G. (2024). Two distinct molecular cloud populations detected in massive galaxies. Monthly Notices of the Royal Astronomical Society, 533(1), 771-794. https://doi.org/10.1093/mnras/stae1831

We present new ALMA observations of CO, CN, CS, HCN, and HCO+ absorption seen against the bright and compact radio continuum sources of eight galaxies. Combined with archival observations, they reveal two distinct populations of molecular clouds, whi... Read More about Two distinct molecular cloud populations detected in massive galaxies.

The Evolution of Galaxies and Clusters at High Spatial Resolution with Advanced X-ray Imaging Satellite (AXIS) (2024)
Journal Article
Russell, H. R., Lopez, L. A., Allen, S. W., Chartas, G., Choudhury, P. P., Dupke, R. A., Fabian, A. C., Flores, A. M., Garofali, K., Hodges-Kluck, E., Koss, M. J., Lanz, L., Lehmer, B. D., Li, J.-T., Maksym, W. P., Mantz, A. B., McDonald, M., Miller, E. D., Mushotzky, R. F., Qiu, Y., …Zhang, C. (2024). The Evolution of Galaxies and Clusters at High Spatial Resolution with Advanced X-ray Imaging Satellite (AXIS). Universe, 10(7), Article 273. https://doi.org/10.3390/universe10070273

Stellar and black hole feedback heat and disperse surrounding cold gas clouds, launching gas flows off circumnuclear and galactic disks, producing a dynamic interstellar medium. On large scales bordering the cosmic web, feedback drives enriched gas o... Read More about The Evolution of Galaxies and Clusters at High Spatial Resolution with Advanced X-ray Imaging Satellite (AXIS).

A cooling flow around the low-redshift quasar H1821+643 (2024)
Journal Article
Russell, H. R., Nulsen, P. E., Fabian, A. C., Braben, T. E., Brandt, W. N., Clews, L., McDonald, M., Reynolds, C. S., Sanders, J. S., & Veilleux, S. (2024). A cooling flow around the low-redshift quasar H1821+643. Monthly Notices of the Royal Astronomical Society, 528(2), 1863–1878. https://doi.org/10.1093/mnras/stae026

H1821+643 is the nearest quasar hosted by a galaxy cluster. The energy output by the quasar, in the form of intense radiation and radio jets, is captured by the surrounding hot atmosphere. Here, we present a new deep Chandra observation of H1821+643... Read More about A cooling flow around the low-redshift quasar H1821+643.

A massive multiphase plume of gas in Abell 2390's brightest cluster galaxy (2024)
Journal Article
Rose, T., McNamara, B. R., Combes, F., Edge, A. C., Russell, H., Salomé, P., Tamhane, P., Fabian, A. C., & Tremblay, G. (2024). A massive multiphase plume of gas in Abell 2390's brightest cluster galaxy. Monthly Notices of the Royal Astronomical Society, 528(2), 3441–3455. https://doi.org/10.1093/mnras/stae213

We present new ALMA CO(2-1) observations tracing 2.2 × 10 10 M ⊙ of molecular gas in Abell 2390's brightest cluster galaxy, where half the gas is located in a one-sided plume extending 15 kpc out from the galaxy centre. This molecular gas has a smoot... Read More about A massive multiphase plume of gas in Abell 2390's brightest cluster galaxy.

Constraints on thermal conductivity in the merging cluster Abell 2146 (2023)
Journal Article
Richard-Laferrière, A., Russell, H. R., Fabian, A. C., Chadayammuri, U., Reynolds, C. S., Canning, R. E. A., Edge, A. C., Hlavacek-Larrondo, J., King, L. J., Mcnamara, B. R., Nulsen, P. E. J., & Sanders, J. S. (2023). Constraints on thermal conductivity in the merging cluster Abell 2146. Monthly Notices of the Royal Astronomical Society, 526(4), 6205–6213. https://doi.org/10.1093/mnras/stad3101

The cluster of galaxies Abell 2146 is undergoing a major merger and is an ideal cluster to study ICM physics, as it has a simple geometry with the merger axis in the plane of the sky, its distance allows us to resolve features across the relevant sca... Read More about Constraints on thermal conductivity in the merging cluster Abell 2146.

Overview of the Advanced X-ray Imaging Satellite (AXIS) (2023)
Presentation / Conference Contribution
Reynolds, C. S., Kara, E. A., Mushotzky, R. F., Ptak, A., Koss, M. J., Williams, B. J., Allen, S. W., Bauer, F. E., Bautz, M., Bodaghee, A., Burdge, K. B., Cappelluti, N., Cenko, B., Chartas, G., Chan, K.-W., Corrales, L., Daylan, T., Falcone, A. D., Foord, A., Grant, C. E., …Zhang, W. W. (2023, August). Overview of the Advanced X-ray Imaging Satellite (AXIS). Presented at SPIE Optical Engineering + Applications, 2023, San Diego, USA

The Advanced X-ray Imaging Satellite (AXIS) is a Probe-class concept that will build on the legacy of the Chandra X-ray Observatory by providing low-background, arcsecond-resolution imaging in the 0.3-10 keV band across a 450 arcminute 2 field of vie... Read More about Overview of the Advanced X-ray Imaging Satellite (AXIS).

AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius (2023)
Journal Article
Bambic, C. J., Russell, H. R., Reynolds, C. S., Fabian, A. C., McNamara, B. R., & Nulsen, P. E. J. (2023). AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius. Monthly Notices of the Royal Astronomical Society, 522(3), 4374-4391. https://doi.org/10.1093/mnras/stad824

We present the deepest Chandra observation to date of the galaxy M84 in the Virgo Cluster, with over 840 ks of data provided by legacy observations and a recent 730 ks campaign. The increased signal-to-noise ratio allows us to study the origins of th... Read More about AGN feeding and feedback in M84: from kiloparsec scales to the Bondi radius.

Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies (2022)
Journal Article
Calzadilla, M. S., McDonald, M., Donahue, M., McNamara, B. R., Fogarty, K., Gaspari, M., Gitti, M., Russell, H. R., Tremblay, G. R., Voit, G. M., & Ubertosi, F. (2022). Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies. Astrophysical Journal, 940(2), Article 140. https://doi.org/10.3847/1538-4357/ac9790

We present new, deep, narrow- and broadband Hubble Space Telescope observations of seven of the most star-forming brightest cluster galaxies (BCGs). Continuum-subtracted [OII] maps reveal the detailed, complex structure of warm (T ∼ 104 K) ionized ga... Read More about Testing the Limits of AGN Feedback and the Onset of Thermal Instability in the Most Rapidly Star-forming Brightest Cluster Galaxies.

The structure of cluster merger shocks: turbulent width and the electron heating time-scale (2022)
Journal Article
Russell, H. R., Nulsen, P. E. J., Caprioli, D., Chadayammuri, U., Fabian, A. C., Kunz, M. W., McNamara, B. R., Sanders, J. S., Richard-Laferrière, A., Beleznay, M., Canning, R. E. A., Hlavacek-Larrondo, J., & King, L. .. (2022). The structure of cluster merger shocks: turbulent width and the electron heating time-scale. Monthly Notices of the Royal Astronomical Society, 514(1), 1477-1493. https://doi.org/10.1093/mnras/stac1055

We present a new 2 Ms Chandra observation of the cluster merger Abell 2146, which hosts two huge M∼2 shock fronts each ∼500 kpc across. For the first time, we resolve and measure the width of cluster merger shocks. The best-fit width for the bow shoc... Read More about The structure of cluster merger shocks: turbulent width and the electron heating time-scale.

Turbulent magnetic fields in merging clusters: a case study of Abell 2146 (2022)
Journal Article
Chadayammuri, U., ZuHone, J., Nulsen, P., Nagai, D., & Russell, H. (2022). Turbulent magnetic fields in merging clusters: a case study of Abell 2146. Monthly Notices of the Royal Astronomical Society, 512(2), 2157-2170. https://doi.org/10.1093/mnras/stac594

Kelvin-Helmholtz instabilities (KHI) along contact discontinuities in galaxy clusters have been used to constrain the strength of magnetic fields in galaxy clusters, following the assumption that, as magnetic field lines drape around the interface be... Read More about Turbulent magnetic fields in merging clusters: a case study of Abell 2146.

New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643 (2021)
Journal Article
Sisk-Reynés, J., Matthews, J. H., Reynolds, C. S., Russell, H. R., Smith, R. N., & Marsh, M. C. (2022). New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643. Monthly Notices of the Royal Astronomical Society, 510(1), 1264-1277. https://doi.org/10.1093/mnras/stab3464

Axion-like particles (ALPs) are predicted by several Beyond the Standard Model theories, in particular, string theory. In the presence of an external magnetic field perpendicular to the direction of propagation, ALPs can couple to photons. Therefore,... Read More about New constraints on light axion-like particles using Chandra transmission grating spectroscopy of the powerful cluster-hosted quasar H1821+643.

Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275 (2020)
Journal Article
Reynolds, C. S., Marsh, M. C. D., Russell, H. R., Fabian, A. C., Smith, R., Tombesi, F., & Veilleux, S. (2020). Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275. Astrophysical Journal, 890(1), Article 59. https://doi.org/10.3847/1538-4357/ab6a0c

Axions/axion-like particles (ALPs) are a well-motivated extension of the Standard Model and are generic within String Theory. The X-ray transparency of the intracluster medium (ICM) in galaxy clusters is a powerful probe of light ALPs (with mass < 10... Read More about Astrophysical Limits on Very Light Axion-like Particles from Chandra Grating Spectroscopy of NGC 1275.

Driving massive molecular gas flows in central cluster galaxies with AGN feedback (2019)
Journal Article
Russell, H. R., McNamara, B. R., Fabian, A. C., Nulsen, P. E. J., Combes, F., Edge, A. C., Madar, M., Olivares, V., Salomé, P., & Vantyghem, A. N. (2019). Driving massive molecular gas flows in central cluster galaxies with AGN feedback. Monthly Notices of the Royal Astronomical Society, 490(3), 3025-3045. https://doi.org/10.1093/mnras/stz2719

We present an analysis of new and archival ALMA observations of molecular gas in twelve central cluster galaxies. We examine emerging trends in molecular filament morphology and gas velocities to understand their origins. Molecular gas masses in thes... Read More about Driving massive molecular gas flows in central cluster galaxies with AGN feedback.

Star formation inside a galactic outflow (2017)
Journal Article
Maiolino, R., Russell, H. R., Fabian, A. C., Carniani, S., Gallagher, R., Cazzoli, S., Arribas, S., Belfiore, F., Bellocchi, E., Colina, L., Cresci, G., Ishibashi, W., Marconi, A., Mannucci, F., Oliva, E., & Sturm, E. (2017). Star formation inside a galactic outflow. Nature, 544(7649), 202-206. https://doi.org/10.1038/nature21677

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Recent observations have revealed massive galactic molecular outflows that may have the physical conditions (high gas densities) required to form stars. Indeed, severa... Read More about Star formation inside a galactic outflow.

Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster (2017)
Journal Article
Aharonian, F. A., Akamatsu, H., Akimoto, F., Allen, S. W., Angelini, L., Arnaud, K. A., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M. W., Blandford, R. D., Bulbul, E., Brenneman, L. W., Brown, G. V., Cackett, E. M., Chernyakova, M., Chiao, M. P., Coppi, P., Costantini, E., …Hitomi Collaboration. (2017). Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster. Astrophysical Journal Letters, 837(1), L15. https://doi.org/10.3847/2041-8213/aa61fa

© 2017. The American Astronomical Society. All rights reserved. High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E ≈ 3.5 keV emission line reported in several low-resolution studies of variou... Read More about Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster.