TY - JOUR
T1 - Expected intermediate-mass black holes in the Virgo cluster - II. Late-type galaxies
AU - Graham, Alister W.
AU - Soria, Roberto
AU - Davis, Benjamin L.
N1 - Publisher Copyright:
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2020
Y1 - 2020
N2 - The Chandra X-ray Observatory's Cycle 18 Large Program titled 'Spiral galaxies of the Virgo Cluster' will image 52 galaxies with the ACIS-S detector. Combined with archival data for an additional 22 galaxies, this will represent the complete sample of 74 spiral galaxies in the Virgo cluster with star formation rates ≳0.3 M☉ yr−1. Many of these galaxies are expected to have an active nucleus, signalling the presence of a central black hole. In preparation for this survey, we predict the central black hole masses using the latest black hole scaling relations based on the spiral arm pitch angle φ, velocity dispersion σ, and total stellar mass M∗,galaxy. With a focus on intermediate-mass black holes (IMBHs; 102 < Mbh/M☉ < 105), we highlight NGC 4713 and NGC 4178, both with Mbh ≈ 103-104 (an estimate that is further supported in NGC 4178 by its nuclear star cluster mass). From Chandra archival data, we find that both galaxies have a point-like nuclear X-ray source, with unabsorbed 0.3-10 keV luminosities of a few times 1038 erg s−1. In NGC 4178, the nuclear source has a soft, probably thermal, spectrum consistent with a stellar-mass black hole in the high/soft state, while no strong constraints can be derived for the nuclear emission of NGC 4713. In total, 33 of the 74 galaxies are predicted to have Mbh < (105-106) M☉, and several are consistently predicted to have masses of 104-105 M☉, such as IC 3392, NGC 4294, and NGC 4413. We speculate that a sizeable population of IMBHs may reside in late-type spiral galaxies with low stellar mass (M∗ ≲ 1010 M☉).
AB - The Chandra X-ray Observatory's Cycle 18 Large Program titled 'Spiral galaxies of the Virgo Cluster' will image 52 galaxies with the ACIS-S detector. Combined with archival data for an additional 22 galaxies, this will represent the complete sample of 74 spiral galaxies in the Virgo cluster with star formation rates ≳0.3 M☉ yr−1. Many of these galaxies are expected to have an active nucleus, signalling the presence of a central black hole. In preparation for this survey, we predict the central black hole masses using the latest black hole scaling relations based on the spiral arm pitch angle φ, velocity dispersion σ, and total stellar mass M∗,galaxy. With a focus on intermediate-mass black holes (IMBHs; 102 < Mbh/M☉ < 105), we highlight NGC 4713 and NGC 4178, both with Mbh ≈ 103-104 (an estimate that is further supported in NGC 4178 by its nuclear star cluster mass). From Chandra archival data, we find that both galaxies have a point-like nuclear X-ray source, with unabsorbed 0.3-10 keV luminosities of a few times 1038 erg s−1. In NGC 4178, the nuclear source has a soft, probably thermal, spectrum consistent with a stellar-mass black hole in the high/soft state, while no strong constraints can be derived for the nuclear emission of NGC 4713. In total, 33 of the 74 galaxies are predicted to have Mbh < (105-106) M☉, and several are consistently predicted to have masses of 104-105 M☉, such as IC 3392, NGC 4294, and NGC 4413. We speculate that a sizeable population of IMBHs may reside in late-type spiral galaxies with low stellar mass (M∗ ≲ 1010 M☉).
KW - Black hole physics
KW - Galaxies: individual: IC 3392, NGC 4178, NGC 4294, NGC 4413, NGC 4470, NGC 4713
KW - Galaxies: spiral
KW - Galaxies: structure
KW - X-rays: galaxies
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U2 - 10.1093/mnras/sty3068
DO - 10.1093/mnras/sty3068
M3 - Article
AN - SCOPUS:85063389691
SN - 0035-8711
VL - 484
SP - 814
EP - 831
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -