NuSTAR Observations of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-only Scenario
نویسندگان
چکیده
We utilize recent NuSTAR observations (co-added depth $\approx55$-120 ks) of PG $1001+054$, $1254+047$, and PHL 1811 to constrain their hard X-ray ($\gtrsim5$ keV) weakness spectral shapes, thus investigate the nature extreme weakness. These quasars showed very weak soft emission, they were proposed be intrinsically weak, with coronae producing continuum emission relative optical/UV emission. However, new suggest an alternative explanation. The 3-24 keV shapes for $1001+054$ are likely flat (effective power-law photon indices $\Gamma_{\rm eff}=1.0^{+0.5}_{-0.6}$ eff}=1.4^{+0.8}_{-0.7}$, respectively), while shape is nominal $1254+047$ ($\Gamma_{\rm eff}=1.8\pm0.3$). significantly at energies (by factors $\approx26$-74 rest-frame 8 compared expectations from only by a factor $\approx3$. that obscuration present in all three quasars. propose that, as intrinsic + scenario, these can uniformly explained under obscuration-only scenario. This model provides adequate descriptions multi-epoch data quasars, variable column density leaked fraction partial-covering absorber. absorber clumpy dust-free wind launched accretion disk. probably have super-Eddington rates drive powerful high-density winds.
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2022
ISSN: ['2041-8213', '2041-8205']
DOI: https://doi.org/10.3847/1538-4357/ac886e