Koki Kakiichi, Tobias Schmidt, Joseph Hennawi, Photometric IGM tomography: Efficiently mapping quasar light echoes with deep narrow-band imaging, Monthly Notices of the Royal Astronomical Society, Volume 516, Issue 1, October 2022, Pages 582–601, https://doi.org/10.1093/mnras/stac2026

In the standard picture, episodes of luminous quasar activity are directly related to supermassive black hole (SMBH) growth. The ionizing radiation emitted over a quasar’s lifetime alters the ionization state of the surrounding intergalactic medium (IGM), enhancing the Lyα forest transmission – so-called proximity effect – which can be observed in absorption spectra of background sources. Owing to the finite speed of light, the transverse direction of the proximity effect is sensitive to the quasar’s radiative history, resulting in ‘light echoes’ that encode the growth history of the SMBH on Myr time-scales. In this paper, we introduce a new technique to photometrically map this quasar light echoes using Lyα forest tomography by using a carefully selected pair of narrow-band filters. A foreground narrow-band filter is used to measure Lyα forest transmission along background galaxies selected as Lyα emitters by a background narrow-band filter. This novel double narrow-band tomographic technique utilizes the higher throughput and wider field of view of imaging over spectroscopy to efficiently reconstruct a two-dimensional map of Lyα forest transmission around a quasar. We present a fully Bayesian framework to measure the luminous quasar lifetime of a SMBH from photometric IGM tomography, and examine the observational requirements. This new technique provides an efficient strategy to map a large area of the sky with a modest observing time and to identify interesting regions to be examined by further deep 3D follow-up spectroscopic Lyα forest tomography.

Access to content on Oxford Academic is often provided through institutional subscriptions and purchases. If you are a member of an institution with an active account, you may be able to access content in one of the following ways:

Typically, access is provided across an institutional network to a range of IP addresses. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.

Choose this option to get remote access when outside your institution. Shibboleth / Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic.

If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.

Enter your library card number to sign in. If you cannot sign in, please contact your librarian.

Society member access to a journal is achieved in one of the following ways:

Many societies offer single sign-on between the society website and Oxford Academic. If you see ‘Sign in through society site’ in the sign in pane within a journal:

If you do not have a society account or have forgotten your username or password, please contact your society.

Some societies use Oxford Academic personal accounts to provide access to their members. See below.

A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions.

Some societies use Oxford Academic personal accounts to provide access to their members.

Click the account icon in the top right to:

Oxford Academic is home to a wide variety of products. The institutional subscription may not cover the content that you are trying to access. If you believe you should have access to that content, please contact your librarian.

For librarians and administrators, your personal account also provides access to institutional account management. Here you will find options to view and activate subscriptions, manage institutional settings and access options, access usage statistics, and more.

To purchase short term access, please sign in to your Oxford Academic account above.

Don't already have an Oxford Academic account? Register

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.