Teacup galaxy

Did You Know?

• The quasar has dimmed by only a factor of 25 or less over the past 100,000 years.
• VLT/SINFONI observations showed a blueshifted nuclear outflow with a velocity of 1600–1800 km/s.

Galaxy

The Teacup galaxy is bulge-dominated and asymmetric, with a shell-like structure and a tidal tail that indicate a recent merger of two galaxies. Dust lanes suggest a gas-rich merger. Hubble Space Telescope images have identified several candidate star clusters. Observations with the Gran Telescopio Canarias reveal a giant reservoir of ionized gas extending up to 111 kpc, across which optical and radio bubbles appear to be expanding.

Bubbles

Galaxy Zoo volunteers discovered a 5 kpc loop of ionized gas in SDSS images, dominated by emission lines such as hydrogen alpha and doubly ionized oxygen, giving it a purple color. The [O II] emission is extremely strong in the Teacup AGN, and the quasar 3C 48 shows a similar [O II]/Hβ ratio. Follow-up Very Large Array observations revealed two 10–12 kpc bubbles: an eastern bubble consistent with the optical loop and a western bubble visible only in radio. A bright emission northeast of the AGN corresponds to high-velocity ionized gas at -740 km/s. The bubbles may be created by small-scale radio jets or quasar winds. Chandra data show an x-ray loop matching the eastern bubble and evidence for hotter gas inside, suggesting a wind of material blowing away from the black hole, possibly driven by radiation from the quasar. VLT/MUSE observations indicate the jet strongly perturbs the host interstellar medium, with a ≤100–150 Myr young stellar population at the bubble edge, indicating triggered star formation. ALMA observations found that the radio jet compresses and accelerates molecular gas, driving a lateral outflow perpendicular to the jet, based on carbon monoxide (CO) gas observations.