With two central galaxies engaged in a major merger and a remarkable chain of 19 young stellar superclusters wound around them in projection, the galaxy cluster SDSS J1531+3414 (
Probing Multiphase Gas in Local Massive Elliptical Galaxies via Multiwavelength Observations
Abstract We investigate the cold and warm gas content, kinematics, and spatial distribution of six local massive elliptical galaxies to probe the origin of the multiphase gas in their atmospheres. We report new observations, including Stratospheric Observatory for Infrared Astronomy [C ii ], Atacama Large Millimeter/submillimeter Array CO, Multi Unit Spectroscopic Explorer (MUSE) H α +[N ii ], and Very Large Array (VLA) radio observations. These are complemented by a large suite of multiwavelength archival data sets, including thermodynamical properties of the hot gas and radio jets, which are leveraged to investigate the role of active galactic nucleus (AGN) feeding/feedback in regulating the multiphase gas content. Our galactic sample shows a significant diversity in cool gas content, spanning filamentary and rotating structures. In our noncentral galaxies, the distribution of such gas is often concentrated, at variance with the more extended features observed in central galaxies. Misalignment between the multiphase gas and stars suggest that stellar mass loss is not the primary driver. A fraction of the cool gas might be acquired via galaxy interactions, but we do not find quantitative evidence of mergers in most of our systems. Instead, key evidence supports the origin via condensation out of the diffuse halo. Comparing with chaotic cold accretion (CCA) simulations, we find that our cool gas-free galaxies are likely in the overheated phase of the self-regulated AGN cycle, while for our galaxies with cool gas, the k-plot and AGN power correlation corroborate the phase of CCA feeding in which the condensation rain is triggering more vigorous AGN heating. The related C-ratio further shows that central/noncentral galaxies are expected to generate an extended/inner rain, consistent with our sample.
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- Award ID(s):
- 1714764
- NSF-PAR ID:
- 10383310
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 928
- Issue:
- 2
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 150
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract z = 0.335) offers an excellent laboratory to study the interplay between mergers, active galactic nucleus (AGN) feedback, and star formation. New Chandra X-ray imaging reveals rapidly cooling hot (T ∼ 106K) intracluster gas, with two “wings” forming a concave density discontinuity near the edge of the cool core. LOFAR 144 MHz observations uncover diffuse radio emission strikingly aligned with the “wings,” suggesting that the “wings” are actually the opening to a giant X-ray supercavity. The steep radio emission is likely an ancient relic of one of the most energetic AGN outbursts observed, with 4pV > 1061erg. To the north of the supercavity, GMOS detects warm (T ∼ 104K) ionized gas that enshrouds the stellar superclusters but is redshifted up to +800 km s−1with respect to the southern central galaxy. The Atacama Large Millimeter/submillimeter Array detects a similarly redshifted ∼1010M ⊙reservoir of cold (T ∼ 102K) molecular gas, but it is offset from the young stars by ∼1–3 kpc. We propose that the multiphase gas originated from low-entropy gas entrained by the X-ray supercavity, attribute the offset between the young stars and the molecular gas to turbulent intracluster gas motions, and suggest that tidal interactions stimulated the “beads-on-a-string” star formation morphology. -
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3847/1538-4357/ac5036
