Speaker
Description
The axion is a well-motivated hypothetical particle that could account for dark matter. In strong magnetic fields, such as those surrounding neutron stars and magnetars, axions can convert into photons, a process that could, in principle, produce detectable electromagnetic signatures. Traditionally, searches have focused on the microwave (centimeter wave regime), corresponding to axion masses in the micro–electron volt range. Recent research, however, suggests that the lack of observed axion signals in the cm wave spectra of magnetars may be due to a blue shift caused by the plasma conditions in the magnetosphere. This shift would move any axion-induced electromagnetic signal from the cm into the mm wavelengths, making previous searches at lower frequencies less effective.
Given this possibility, the Atacama Large Millimeter/submillimeter Array (ALMA) is an ideal instrument for a new search strategy. ALMA’s high resolution and sensitivity in the mm wavelengths make it well-suited to detect such blue-shifted axion signals. The magnetar SGR 1745-2900, located near the Galactic Center, is considered one of the most promising sources for this kind of search due to its strong magnetic field and proximity. In this talk, the recent works based on ALMA observations are going to be discussed, along with their implications on the models.
