Line Intensity Mapping with [C II] and CO(1-0) as Probes of Primordial Non-Gaussianity
Abstract
Constraints on primordial non-Gaussianity (PNG) will shed light on the origin of primordial fluctuations and the physics of the early universe. The intensity mapping technique is a promising probe of structure formation on large scales; at high redshifts, it can provide complementary information to other cosmological probes. We explore the potential of future wide-field [C II] and CO intensity mapping surveys in constraining PNG of the local shape, which induces a distinct, scale-dependent correction to the line bias. We explore the parameter space of CO and [C II] survey designs that can achieve the nominal target of σ ({f}NL}loc})=1, and further calculate what constraints such surveys can place on PNG of the equilateral, orthogonal, and quasi-single field shapes. We further test the dependence of these constraints on various model assumptions; namely the halo mass function, modeling of line bias, and correlation between mass and [C II]/CO luminosity. We find that the ability of CO and [C II] intensity mapping surveys to constrain {f}NL}loc} relies heavily on the spectral (redshift) coverage, requiring at least a coverage of an octave in frequency, to produce significant results, with the optimized surveys generally covering between z ∼ [2-8]. As this redshift window partially overlaps with 21 cm EoR experiments like the Hydrogen Epoch of Reionization Array (HERA), we additionally explore the prospects for a hypothetical set of surveys to place constraints on σ ({f}NL}loc}) utilizing multi-tracer analysis between the lines of H I, CO, and [C II].
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2019
- DOI:
- 10.3847/1538-4357/aafd36
- arXiv:
- arXiv:1810.02850
- Bibcode:
- 2019ApJ...872..126M
- Keywords:
-
- early universe;
- galaxies: high-redshift;
- large-scale structure of universe;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- Version 2 matches the published version in APJ