TY - JOUR
T1 - A quasar-galaxy merger at z ~ 6.2
T2 - Black hole mass and quasar properties from the NIRSpec spectrum
AU - Loiacono, Federica
AU - Decarli, Roberto
AU - Mignoli, Marco
AU - Farina, Emanuele Paolo
AU - Bañados, Eduardo
AU - Bosman, Sarah
AU - Eilers, Anna Christina
AU - Schindler, Jan Torge
AU - Strauss, Michael A.
AU - Vestergaard, Marianne
AU - Wang, Feige
AU - Blecha, Laura
AU - Carilli, Chris L.
AU - Comastri, Andrea
AU - Connor, Thomas
AU - Costa, Tiago
AU - Dotti, Massimo
AU - Fan, Xiaohui
AU - Gilli, Roberto
AU - Jun, Hyunsung D.
AU - Liu, Weizhe
AU - Lupi, Alessandro
AU - Marshall, Madeline A.
AU - Mazzucchelli, Chiara
AU - Meyer, Romain A.
AU - Neeleman, Marcel
AU - Overzier, Roderik
AU - Pensabene, Antonio
AU - Riechers, Dominik A.
AU - Trakhtenbrot, Benny
AU - Trebitsch, Maxime
AU - Venemans, Bram
AU - Walter, Fabian
AU - Yang, Jinyi
N1 - Publisher Copyright:
© 2024 EDP Sciences. All rights reserved.
PY - 2024/5/1
Y1 - 2024/5/1
N2 - We present JWST/NIRSpec integral field data of the quasar PJ308-21 at z = 6.2342. As shown by previous ALMA and HST imaging, the quasar has two companion sources, interacting with the quasar host galaxy. The high-resolution G395H/290LP NIRSpec spectrum covers the 2.87 - 5.27μm wavelength range and shows the rest-frame optical emission of the quasar with exquisite quality (signal-to-noise ratio ~100 - 400 per spectral element). Based on the Hβ line from the broad line region, we obtain an estimate of the black hole mass MBH,Hβ ~ 2.7 × 109M⊙. This value is within a factor ≲1.5 of the Hα-based black hole mass from the same spectrum (MBH,Hα ~ 1.93 × 109M⊙) and is consistent with a previous estimate relying on the Mg IIλ2799 line (MBH,MgII ~ 2.65 × 109M⊙). All these MBH estimates are within the ~0.5 dex intrinsic scatter of the adopted mass calibrations. The high Eddington ratio of PJ308-21 λEdd,Hβ ~ 0.67 (λEdd,Hα ~ 0.96) is in line with the overall quasar population at z ≳ 6. The relative strengths of the [O III], Fe II, and Hβ lines are consistent with the empirical "Eigenvector 1"correlations as observed for low redshift quasars. We find evidence for blueshifted [O III] λ5007 emission with a velocity offset δv[O III] = -1922 ± 39 km s-1 from the systemic velocity and a full width at half maximum (FWHM) FWHM([O III]) = 2776-74+75 km s-1. This may be the signature of outflowing gas from the nuclear region, despite the true values of δv[O III] and FWHM([O III]) likely being more uncertain due to the blending with Hβ and Fe II lines. Our study demonstrates the unique capabilities of NIRSpec in capturing quasar spectra at cosmic dawn and studying their properties in unprecedented detail.
AB - We present JWST/NIRSpec integral field data of the quasar PJ308-21 at z = 6.2342. As shown by previous ALMA and HST imaging, the quasar has two companion sources, interacting with the quasar host galaxy. The high-resolution G395H/290LP NIRSpec spectrum covers the 2.87 - 5.27μm wavelength range and shows the rest-frame optical emission of the quasar with exquisite quality (signal-to-noise ratio ~100 - 400 per spectral element). Based on the Hβ line from the broad line region, we obtain an estimate of the black hole mass MBH,Hβ ~ 2.7 × 109M⊙. This value is within a factor ≲1.5 of the Hα-based black hole mass from the same spectrum (MBH,Hα ~ 1.93 × 109M⊙) and is consistent with a previous estimate relying on the Mg IIλ2799 line (MBH,MgII ~ 2.65 × 109M⊙). All these MBH estimates are within the ~0.5 dex intrinsic scatter of the adopted mass calibrations. The high Eddington ratio of PJ308-21 λEdd,Hβ ~ 0.67 (λEdd,Hα ~ 0.96) is in line with the overall quasar population at z ≳ 6. The relative strengths of the [O III], Fe II, and Hβ lines are consistent with the empirical "Eigenvector 1"correlations as observed for low redshift quasars. We find evidence for blueshifted [O III] λ5007 emission with a velocity offset δv[O III] = -1922 ± 39 km s-1 from the systemic velocity and a full width at half maximum (FWHM) FWHM([O III]) = 2776-74+75 km s-1. This may be the signature of outflowing gas from the nuclear region, despite the true values of δv[O III] and FWHM([O III]) likely being more uncertain due to the blending with Hβ and Fe II lines. Our study demonstrates the unique capabilities of NIRSpec in capturing quasar spectra at cosmic dawn and studying their properties in unprecedented detail.
KW - Galaxies: ISM
KW - Galaxies: high-redshift
KW - Quasars: individual: PJ308-21
KW - Quasars: supermassive black holes
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U2 - 10.1051/0004-6361/202348535
DO - 10.1051/0004-6361/202348535
M3 - Article
AN - SCOPUS:85193426897
SN - 0004-6361
VL - 685
JO - Astronomy and astrophysics
JF - Astronomy and astrophysics
M1 - A121
ER -