---
res:
  bibo_abstract:
  - Emission from two massive black holes (MBHs) bound in a close binary is expected
    to be modulated by different processes, such as the Doppler boost due to the orbital
    motion, accretion rate variability generated by the interaction with a circumbinary
    disc, and binary gravitational self-lensing. When the binary is compact enough,
    the two black holes are thought to be surrounded by a common broad-line region
    that reprocesses the impinging periodically varying ionising flux, creating broad
    emission lines with variable line shapes. Therefore, the study of broad emission
    line variability through multi-epoch spectroscopic campaigns is of paramount importance
    for the unambiguous identification of a binary. In this work, we study the response
    of a disc-like broad-line region to the Doppler-boosted ionising flux emitted
    by sub-milliparsec MBH binaries on a circular orbit and compare it with the response
    of a broad-line region illuminated by a single MBH with a periodically but isotropically
    varying intrinsic luminosity. We show that in the binary case, the time lags of
    the blue and red wings of the broad emission lines, arising from diametrically
    opposite sides of the circumbinary disc, are out of phase by half of the binary’s
    orbital period, as they each respond to the periodic ‘lighthouse’ modulation from
    the binary’s continuum emission. This asymmetric time lag represents a new binary
    signature that cannot be mimicked by a single MBH.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Lorenzo
      foaf_name: Bertassi, Lorenzo
      foaf_surname: Bertassi
  - foaf_Person:
      foaf_givenName: Erika
      foaf_name: Sottocorno, Erika
      foaf_surname: Sottocorno
  - foaf_Person:
      foaf_givenName: Fabio
      foaf_name: Rigamonti, Fabio
      foaf_surname: Rigamonti
  - foaf_Person:
      foaf_givenName: Daniel
      foaf_name: D’Orazio, Daniel
      foaf_surname: D’Orazio
  - foaf_Person:
      foaf_givenName: Michael
      foaf_name: Eracleous, Michael
      foaf_surname: Eracleous
  - foaf_Person:
      foaf_givenName: Zoltán
      foaf_name: Haiman, Zoltán
      foaf_surname: Haiman
      foaf_workInfoHomepage: http://www.librecat.org/personId=7c006e8c-cc0d-11ee-8322-cb904ef76f36
    orcid: 0000-0003-3633-5403
  - foaf_Person:
      foaf_givenName: Massimo
      foaf_name: Dotti, Massimo
      foaf_surname: Dotti
  bibo_doi: 10.1051/0004-6361/202554574
  bibo_volume: 702
  dct_date: 2025^xs_gYear
  dct_identifier:
  - UT:001597841900015
  dct_isPartOf:
  - http://id.crossref.org/issn/0004-6361
  - http://id.crossref.org/issn/1432-0746
  dct_language: eng
  dct_publisher: EDP Sciences@
  dct_title: Testing compact massive black hole binary candidates through multi-epoch
    spectroscopy@
...