High-energy neutrino and γ-ray emission are expected from the Galactic plane, produced by interactions between cosmic rays and the interstellar medium or radiation fields. Recent LHAASO observations have detected diffuse γ-rays from the Galactic plane and an ultrahigh-energy γ-ray bubble (Cygnus Bubble) up to PeV energies, suggesting the possibility of neutrino emission. Using 7 years of publicly available IceCube track data with the full detector, we conducted searches for neutrino signals correlated with LHAASO diffuse Galactic γ-ray emission and Cygnus Bubble using a template method. A mild excess of neutrinos is observed in the Galactic plane. 
Complementary to these steady-source searches, we search for variable extragalactic neutrino sources. IceCube issues real-time high-energy (HE) neutrino alerts and has released its first catalog, IceCat-1. The origin of these neutrinos remains largely unknown. Active galactic nuclei (AGNs) exhibiting variability are promising candidate sources, with previous studies hinting at temporal correlations between HE neutrino alerts and infrared flares. We perform a spatio-temporal correlation analysis between IceCube HE neutrino alerts and a sample of WISE-selected AGNs and radio-loud blazars, cross-matched with the Fermi-LAT 4FGL-DR2 catalog, across the infrared and γ-ray bands. Additionally, we investigate the multi-wavelength behavior of promising source candidates, from radio to -rays.